Auto merge of #31349 - nikomatsakis:issue-31157-obligation-forest-cache, r=aturon
Have the `ObligationForest` keep some per-tree state (or type `T`) and have it give a mutable reference for use when processing obligations. In this case, it will be a hashmap. This obviously affects the work that @soltanmm has been doing on snapshotting. I partly want to toss this out there for discussion. Fixes #31157. (The test in question goes to approx. 30s instead of 5 minutes for me.) cc #30977. cc @aturon @arielb1 @soltanmm r? @aturon who reviewed original `ObligationForest`
This commit is contained in:
commit
6dc112dbb7
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@ -36,6 +36,7 @@ pub struct GlobalFulfilledPredicates<'tcx> {
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dep_graph: DepGraph,
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}
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#[derive(Debug)]
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pub struct LocalFulfilledPredicates<'tcx> {
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set: FnvHashSet<ty::Predicate<'tcx>>
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}
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@ -66,7 +67,8 @@ pub struct FulfillmentContext<'tcx> {
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// A list of all obligations that have been registered with this
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// fulfillment context.
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predicates: ObligationForest<PendingPredicateObligation<'tcx>>,
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predicates: ObligationForest<PendingPredicateObligation<'tcx>,
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LocalFulfilledPredicates<'tcx>>,
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// A set of constraints that regionck must validate. Each
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// constraint has the form `T:'a`, meaning "some type `T` must
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@ -192,7 +194,7 @@ impl<'tcx> FulfillmentContext<'tcx> {
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obligation: obligation,
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stalled_on: vec![]
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};
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self.predicates.push_root(obligation);
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self.predicates.push_tree(obligation, LocalFulfilledPredicates::new());
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}
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pub fn region_obligations(&self,
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@ -278,10 +280,11 @@ impl<'tcx> FulfillmentContext<'tcx> {
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let outcome = {
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let region_obligations = &mut self.region_obligations;
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self.predicates.process_obligations(
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|obligation, backtrace| process_predicate(selcx,
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obligation,
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backtrace,
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region_obligations))
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|obligation, tree, backtrace| process_predicate(selcx,
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tree,
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obligation,
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backtrace,
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region_obligations))
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};
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debug!("select_where_possible: outcome={:?}", outcome);
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@ -315,61 +318,97 @@ impl<'tcx> FulfillmentContext<'tcx> {
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/// Like `process_predicate1`, but wrap result into a pending predicate.
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fn process_predicate<'a,'tcx>(selcx: &mut SelectionContext<'a,'tcx>,
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tree_cache: &mut LocalFulfilledPredicates<'tcx>,
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pending_obligation: &mut PendingPredicateObligation<'tcx>,
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backtrace: Backtrace<PendingPredicateObligation<'tcx>>,
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mut backtrace: Backtrace<PendingPredicateObligation<'tcx>>,
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region_obligations: &mut NodeMap<Vec<RegionObligation<'tcx>>>)
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-> Result<Option<Vec<PendingPredicateObligation<'tcx>>>,
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FulfillmentErrorCode<'tcx>>
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{
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match process_predicate1(selcx, pending_obligation, backtrace, region_obligations) {
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match process_predicate1(selcx, pending_obligation, backtrace.clone(), region_obligations) {
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Ok(Some(v)) => {
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// FIXME(#30977) the right thing to do here, I think, is to permit
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// DAGs. That is, we should detect whenever this predicate
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// has appeared somewhere in the current tree./ If it's a
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// parent, that's a cycle, and we should either error out
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// or consider it ok. But if it's NOT a parent, we can
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// ignore it, since it will be proven (or not) separately.
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// However, this is a touch tricky, so I'm doing something
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// a bit hackier for now so that the `huge-struct.rs` passes.
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// FIXME(#30977) The code below is designed to detect (and
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// permit) DAGs, while still ensuring that the reasoning
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// is acyclic. However, it does a few things
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// suboptimally. For example, it refreshes type variables
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// a lot, probably more than needed, but also less than
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// you might want.
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//
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// - more than needed: I want to be very sure we don't
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// accidentally treat a cycle as a DAG, so I am
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// refreshing type variables as we walk the ancestors;
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// but we are going to repeat this a lot, which is
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// sort of silly, and it would be nicer to refresh
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// them *in place* so that later predicate processing
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// can benefit from the same work;
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// - less than you might want: we only add items in the cache here,
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// but maybe we learn more about type variables and could add them into
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// the cache later on.
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let tcx = selcx.tcx();
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let retain_vec: Vec<_> = {
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let mut dedup = FnvHashSet();
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v.iter()
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.map(|o| {
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// Compute a little FnvHashSet for the ancestors. We only
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// do this the first time that we care.
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let mut cache = None;
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let mut is_ancestor = |predicate: &ty::Predicate<'tcx>| {
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if cache.is_none() {
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let mut c = FnvHashSet();
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for ancestor in backtrace.by_ref() {
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// Ugh. This just feels ridiculously
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// inefficient. But we need to compare
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// predicates without being concerned about
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// the vagaries of type inference, so for now
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// just ensure that they are always
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// up-to-date. (I suppose we could just use a
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// snapshot and check if they are unifiable?)
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let resolved_predicate =
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selcx.infcx().resolve_type_vars_if_possible(
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&ancestor.obligation.predicate);
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c.insert(resolved_predicate);
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}
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cache = Some(c);
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}
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cache.as_ref().unwrap().contains(predicate)
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};
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let pending_predicate_obligations: Vec<_> =
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v.into_iter()
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.filter_map(|obligation| {
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// Probably silly, but remove any inference
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// variables. This is actually crucial to the
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// ancestor check below, but it's not clear that
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// it makes sense to ALWAYS do it.
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let obligation = selcx.infcx().resolve_type_vars_if_possible(&obligation);
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// Screen out obligations that we know globally
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// are true. This should really be the DAG check
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// mentioned above.
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if tcx.fulfilled_predicates.borrow().check_duplicate(&o.predicate) {
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return false;
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if tcx.fulfilled_predicates.borrow().check_duplicate(&obligation.predicate) {
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return None;
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}
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// If we see two siblings that are exactly the
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// same, no need to add them twice.
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if !dedup.insert(&o.predicate) {
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return false;
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// Check whether this obligation appears somewhere else in the tree.
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if tree_cache.is_duplicate_or_add(&obligation.predicate) {
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// If the obligation appears as a parent,
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// allow it, because that is a cycle.
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// Otherwise though we can just ignore
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// it. Note that we have to be careful around
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// inference variables here -- for the
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// purposes of the ancestor check, we retain
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// the invariant that all type variables are
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// fully refreshed.
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if !(&mut is_ancestor)(&obligation.predicate) {
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return None;
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}
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}
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true
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Some(PendingPredicateObligation {
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obligation: obligation,
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stalled_on: vec![]
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})
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})
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.collect()
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};
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let pending_predicate_obligations =
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v.into_iter()
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.zip(retain_vec)
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.flat_map(|(o, retain)| {
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if retain {
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Some(PendingPredicateObligation {
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obligation: o,
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stalled_on: vec![]
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})
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} else {
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None
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}
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})
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.collect();
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.collect();
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Ok(Some(pending_predicate_obligations))
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}
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@ -405,7 +444,7 @@ fn process_predicate1<'a,'tcx>(selcx: &mut SelectionContext<'a,'tcx>,
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pending_obligation.stalled_on = vec![];
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}
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let obligation = &pending_obligation.obligation;
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let obligation = &mut pending_obligation.obligation;
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// If we exceed the recursion limit, take a moment to look for a
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// cycle so we can give a better error report from here, where we
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@ -417,8 +456,16 @@ fn process_predicate1<'a,'tcx>(selcx: &mut SelectionContext<'a,'tcx>,
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}
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}
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if obligation.predicate.has_infer_types() {
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obligation.predicate = selcx.infcx().resolve_type_vars_if_possible(&obligation.predicate);
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}
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match obligation.predicate {
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ty::Predicate::Trait(ref data) => {
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if selcx.tcx().fulfilled_predicates.borrow().check_duplicate_trait(data) {
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return Ok(Some(vec![]));
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}
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if coinductive_match(selcx, obligation, data, &backtrace) {
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return Ok(Some(vec![]));
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}
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@ -426,9 +473,14 @@ fn process_predicate1<'a,'tcx>(selcx: &mut SelectionContext<'a,'tcx>,
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let trait_obligation = obligation.with(data.clone());
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match selcx.select(&trait_obligation) {
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Ok(Some(vtable)) => {
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info!("selecting trait `{:?}` at depth {} yielded Ok(Some)",
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data, obligation.recursion_depth);
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Ok(Some(vtable.nested_obligations()))
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}
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Ok(None) => {
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info!("selecting trait `{:?}` at depth {} yielded Ok(None)",
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data, obligation.recursion_depth);
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// This is a bit subtle: for the most part, the
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// only reason we can fail to make progress on
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// trait selection is because we don't have enough
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@ -457,6 +509,8 @@ fn process_predicate1<'a,'tcx>(selcx: &mut SelectionContext<'a,'tcx>,
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Ok(None)
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}
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Err(selection_err) => {
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info!("selecting trait `{:?}` at depth {} yielded Err",
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data, obligation.recursion_depth);
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Err(CodeSelectionError(selection_err))
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}
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}
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@ -642,18 +696,28 @@ impl<'tcx> GlobalFulfilledPredicates<'tcx> {
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pub fn check_duplicate(&self, key: &ty::Predicate<'tcx>) -> bool {
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if let ty::Predicate::Trait(ref data) = *key {
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// For the global predicate registry, when we find a match, it
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// may have been computed by some other task, so we want to
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// add a read from the node corresponding to the predicate
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// processing to make sure we get the transitive dependencies.
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if self.set.contains(data) {
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debug_assert!(data.is_global());
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self.dep_graph.read(data.dep_node());
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return true;
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}
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self.check_duplicate_trait(data)
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} else {
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false
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}
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}
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return false;
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pub fn check_duplicate_trait(&self, data: &ty::PolyTraitPredicate<'tcx>) -> bool {
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// For the global predicate registry, when we find a match, it
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// may have been computed by some other task, so we want to
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// add a read from the node corresponding to the predicate
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// processing to make sure we get the transitive dependencies.
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if self.set.contains(data) {
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debug_assert!(data.is_global());
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self.dep_graph.read(data.dep_node());
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debug!("check_duplicate: global predicate `{:?}` already proved elsewhere", data);
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info!("check_duplicate_trait hit: `{:?}`", data);
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true
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} else {
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false
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}
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}
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fn add_if_global(&mut self, key: &ty::Predicate<'tcx>) {
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@ -663,7 +727,10 @@ impl<'tcx> GlobalFulfilledPredicates<'tcx> {
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// already has the required read edges, so we don't need
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// to add any more edges here.
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if data.is_global() {
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self.set.insert(data.clone());
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if self.set.insert(data.clone()) {
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debug!("add_if_global: global predicate `{:?}` added", data);
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info!("check_duplicate_trait entry: `{:?}`", data);
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}
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}
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}
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}
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@ -9,15 +9,18 @@ place).
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`ObligationForest` supports two main public operations (there are a
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few others not discussed here):
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1. Add a new root obligation (`push_root`).
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1. Add a new root obligations (`push_tree`).
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2. Process the pending obligations (`process_obligations`).
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When a new obligation `N` is added, it becomes the root of an
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obligation tree. This tree is a singleton to start, so `N` is both the
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root and the only leaf. Each time the `process_obligations` method is
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called, it will invoke its callback with every pending obligation (so
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that will include `N`, the first time). The callback shoud process the
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obligation `O` that it is given and return one of three results:
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obligation tree. This tree can also carry some per-tree state `T`,
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which is given at the same time. This tree is a singleton to start, so
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`N` is both the root and the only leaf. Each time the
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`process_obligations` method is called, it will invoke its callback
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with every pending obligation (so that will include `N`, the first
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time). The callback also receives a (mutable) reference to the
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per-tree state `T`. The callback should process the obligation `O`
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that it is given and return one of three results:
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- `Ok(None)` -> ambiguous result. Obligation was neither a success
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nor a failure. It is assumed that further attempts to process the
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|
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@ -19,11 +19,16 @@ use std::fmt::Debug;
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use std::mem;
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mod node_index;
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use self::node_index::NodeIndex;
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mod tree_index;
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use self::tree_index::TreeIndex;
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#[cfg(test)]
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mod test;
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pub struct ObligationForest<O> {
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pub struct ObligationForest<O,T> {
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/// The list of obligations. In between calls to
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/// `process_obligations`, this list only contains nodes in the
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/// `Pending` or `Success` state (with a non-zero number of
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@ -37,6 +42,7 @@ pub struct ObligationForest<O> {
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/// at a higher index than its parent. This is needed by the
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/// backtrace iterator (which uses `split_at`).
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nodes: Vec<Node<O>>,
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trees: Vec<Tree<T>>,
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snapshots: Vec<usize>
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}
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@ -44,12 +50,15 @@ pub struct Snapshot {
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len: usize,
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}
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pub use self::node_index::NodeIndex;
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struct Tree<T> {
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root: NodeIndex,
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state: T,
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}
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struct Node<O> {
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state: NodeState<O>,
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parent: Option<NodeIndex>,
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root: NodeIndex, // points to the root, which may be the current node
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tree: TreeIndex,
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}
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/// The state of one node in some tree within the forest. This
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|
@ -99,9 +108,10 @@ pub struct Error<O,E> {
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pub backtrace: Vec<O>,
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}
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impl<O: Debug> ObligationForest<O> {
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pub fn new() -> ObligationForest<O> {
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impl<O: Debug, T: Debug> ObligationForest<O, T> {
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pub fn new() -> ObligationForest<O, T> {
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ObligationForest {
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trees: vec![],
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nodes: vec![],
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snapshots: vec![]
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}
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|
@ -114,30 +124,39 @@ impl<O: Debug> ObligationForest<O> {
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}
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pub fn start_snapshot(&mut self) -> Snapshot {
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self.snapshots.push(self.nodes.len());
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self.snapshots.push(self.trees.len());
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Snapshot { len: self.snapshots.len() }
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}
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pub fn commit_snapshot(&mut self, snapshot: Snapshot) {
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assert_eq!(snapshot.len, self.snapshots.len());
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let nodes_len = self.snapshots.pop().unwrap();
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assert!(self.nodes.len() >= nodes_len);
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let trees_len = self.snapshots.pop().unwrap();
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assert!(self.trees.len() >= trees_len);
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}
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pub fn rollback_snapshot(&mut self, snapshot: Snapshot) {
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// Check that we are obeying stack discipline.
|
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assert_eq!(snapshot.len, self.snapshots.len());
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let nodes_len = self.snapshots.pop().unwrap();
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let trees_len = self.snapshots.pop().unwrap();
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// The only action permitted while in a snapshot is to push
|
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// new root obligations. Because no processing will have been
|
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// done, those roots should still be in the pending state.
|
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debug_assert!(self.nodes[nodes_len..].iter().all(|n| match n.state {
|
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NodeState::Pending { .. } => true,
|
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_ => false,
|
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}));
|
||||
// If nothing happened in snapshot, done.
|
||||
if self.trees.len() == trees_len {
|
||||
return;
|
||||
}
|
||||
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||||
self.nodes.truncate(nodes_len);
|
||||
// Find root of first tree; because nothing can happen in a
|
||||
// snapshot but pushing trees, all nodes after that should be
|
||||
// roots of other trees as well
|
||||
let first_root_index = self.trees[trees_len].root.get();
|
||||
debug_assert!(
|
||||
self.nodes[first_root_index..]
|
||||
.iter()
|
||||
.zip(first_root_index..)
|
||||
.all(|(root, root_index)| self.trees[root.tree.get()].root.get() == root_index));
|
||||
|
||||
// Pop off tree/root pairs pushed during snapshot.
|
||||
self.trees.truncate(trees_len);
|
||||
self.nodes.truncate(first_root_index);
|
||||
}
|
||||
|
||||
pub fn in_snapshot(&self) -> bool {
|
||||
|
@ -147,9 +166,11 @@ impl<O: Debug> ObligationForest<O> {
|
|||
/// Adds a new tree to the forest.
|
||||
///
|
||||
/// This CAN be done during a snapshot.
|
||||
pub fn push_root(&mut self, obligation: O) {
|
||||
pub fn push_tree(&mut self, obligation: O, tree_state: T) {
|
||||
let index = NodeIndex::new(self.nodes.len());
|
||||
self.nodes.push(Node::new(index, None, obligation));
|
||||
let tree = TreeIndex::new(self.trees.len());
|
||||
self.trees.push(Tree { root: index, state: tree_state });
|
||||
self.nodes.push(Node::new(tree, None, obligation));
|
||||
}
|
||||
|
||||
/// Convert all remaining obligations to the given error.
|
||||
|
@ -186,7 +207,7 @@ impl<O: Debug> ObligationForest<O> {
|
|||
///
|
||||
/// This CANNOT be unrolled (presently, at least).
|
||||
pub fn process_obligations<E,F>(&mut self, mut action: F) -> Outcome<O,E>
|
||||
where E: Debug, F: FnMut(&mut O, Backtrace<O>) -> Result<Option<Vec<O>>, E>
|
||||
where E: Debug, F: FnMut(&mut O, &mut T, Backtrace<O>) -> Result<Option<Vec<O>>, E>
|
||||
{
|
||||
debug!("process_obligations(len={})", self.nodes.len());
|
||||
assert!(!self.in_snapshot()); // cannot unroll this action
|
||||
|
@ -210,7 +231,7 @@ impl<O: Debug> ObligationForest<O> {
|
|||
index, self.nodes[index].state);
|
||||
|
||||
let result = {
|
||||
let parent = self.nodes[index].parent;
|
||||
let Node { tree, parent, .. } = self.nodes[index];
|
||||
let (prefix, suffix) = self.nodes.split_at_mut(index);
|
||||
let backtrace = Backtrace::new(prefix, parent);
|
||||
match suffix[0].state {
|
||||
|
@ -218,7 +239,7 @@ impl<O: Debug> ObligationForest<O> {
|
|||
NodeState::Success { .. } =>
|
||||
continue,
|
||||
NodeState::Pending { ref mut obligation } =>
|
||||
action(obligation, backtrace),
|
||||
action(obligation, &mut self.trees[tree.get()].state, backtrace),
|
||||
}
|
||||
};
|
||||
|
||||
|
@ -268,11 +289,11 @@ impl<O: Debug> ObligationForest<O> {
|
|||
self.update_parent(index);
|
||||
} else {
|
||||
// create child work
|
||||
let root_index = self.nodes[index].root;
|
||||
let tree_index = self.nodes[index].tree;
|
||||
let node_index = NodeIndex::new(index);
|
||||
self.nodes.extend(
|
||||
children.into_iter()
|
||||
.map(|o| Node::new(root_index, Some(node_index), o)));
|
||||
.map(|o| Node::new(tree_index, Some(node_index), o)));
|
||||
}
|
||||
|
||||
// change state from `Pending` to `Success`, temporarily swapping in `Error`
|
||||
|
@ -311,8 +332,9 @@ impl<O: Debug> ObligationForest<O> {
|
|||
/// skip the remaining obligations from a tree once some other
|
||||
/// node in the tree is found to be in error.
|
||||
fn inherit_error(&mut self, child: usize) {
|
||||
let root = self.nodes[child].root.get();
|
||||
if let NodeState::Error = self.nodes[root].state {
|
||||
let tree = self.nodes[child].tree;
|
||||
let root = self.trees[tree.get()].root;
|
||||
if let NodeState::Error = self.nodes[root.get()].state {
|
||||
self.nodes[child].state = NodeState::Error;
|
||||
}
|
||||
}
|
||||
|
@ -353,7 +375,8 @@ impl<O: Debug> ObligationForest<O> {
|
|||
/// indices. Cannot be used during a transaction.
|
||||
fn compress(&mut self) -> Vec<O> {
|
||||
assert!(!self.in_snapshot()); // didn't write code to unroll this action
|
||||
let mut rewrites: Vec<_> = (0..self.nodes.len()).collect();
|
||||
let mut node_rewrites: Vec<_> = (0..self.nodes.len()).collect();
|
||||
let mut tree_rewrites: Vec<_> = (0..self.trees.len()).collect();
|
||||
|
||||
// Finish propagating error state. Note that in this case we
|
||||
// only have to check immediate parents, rather than all
|
||||
|
@ -366,43 +389,69 @@ impl<O: Debug> ObligationForest<O> {
|
|||
}
|
||||
}
|
||||
|
||||
// Determine which trees to remove by checking if their root
|
||||
// is popped.
|
||||
let mut dead_trees = 0;
|
||||
let trees_len = self.trees.len();
|
||||
for i in 0..trees_len {
|
||||
let root_node = self.trees[i].root;
|
||||
if self.nodes[root_node.get()].is_popped() {
|
||||
dead_trees += 1;
|
||||
} else if dead_trees > 0 {
|
||||
self.trees.swap(i, i - dead_trees);
|
||||
tree_rewrites[i] -= dead_trees;
|
||||
}
|
||||
}
|
||||
|
||||
// Now go through and move all nodes that are either
|
||||
// successful or which have an error over into to the end of
|
||||
// the list, preserving the relative order of the survivors
|
||||
// (which is important for the `inherit_error` logic).
|
||||
let mut dead = 0;
|
||||
let mut dead_nodes = 0;
|
||||
for i in 0..nodes_len {
|
||||
if self.nodes[i].is_popped() {
|
||||
dead += 1;
|
||||
} else if dead > 0 {
|
||||
self.nodes.swap(i, i - dead);
|
||||
rewrites[i] -= dead;
|
||||
dead_nodes += 1;
|
||||
} else if dead_nodes > 0 {
|
||||
self.nodes.swap(i, i - dead_nodes);
|
||||
node_rewrites[i] -= dead_nodes;
|
||||
}
|
||||
}
|
||||
|
||||
// No compression needed.
|
||||
if dead_nodes == 0 && dead_trees == 0 {
|
||||
return vec![];
|
||||
}
|
||||
|
||||
// Pop off the trees we killed.
|
||||
self.trees.truncate(trees_len - dead_trees);
|
||||
|
||||
// Pop off all the nodes we killed and extract the success
|
||||
// stories.
|
||||
let successful =
|
||||
(0 .. dead).map(|_| self.nodes.pop().unwrap())
|
||||
.flat_map(|node| match node.state {
|
||||
NodeState::Error => None,
|
||||
NodeState::Pending { .. } => unreachable!(),
|
||||
NodeState::Success { obligation, num_incomplete_children } => {
|
||||
assert_eq!(num_incomplete_children, 0);
|
||||
Some(obligation)
|
||||
}
|
||||
})
|
||||
.collect();
|
||||
(0 .. dead_nodes)
|
||||
.map(|_| self.nodes.pop().unwrap())
|
||||
.flat_map(|node| match node.state {
|
||||
NodeState::Error => None,
|
||||
NodeState::Pending { .. } => unreachable!(),
|
||||
NodeState::Success { obligation, num_incomplete_children } => {
|
||||
assert_eq!(num_incomplete_children, 0);
|
||||
Some(obligation)
|
||||
}
|
||||
})
|
||||
.collect();
|
||||
|
||||
// Adjust the parent indices, since we compressed things.
|
||||
// Adjust the various indices, since we compressed things.
|
||||
for tree in &mut self.trees {
|
||||
tree.root = NodeIndex::new(node_rewrites[tree.root.get()]);
|
||||
}
|
||||
for node in &mut self.nodes {
|
||||
if let Some(ref mut index) = node.parent {
|
||||
let new_index = rewrites[index.get()];
|
||||
debug_assert!(new_index < (nodes_len - dead));
|
||||
let new_index = node_rewrites[index.get()];
|
||||
debug_assert!(new_index < (nodes_len - dead_nodes));
|
||||
*index = NodeIndex::new(new_index);
|
||||
}
|
||||
|
||||
node.root = NodeIndex::new(rewrites[node.root.get()]);
|
||||
node.tree = TreeIndex::new(tree_rewrites[node.tree.get()]);
|
||||
}
|
||||
|
||||
successful
|
||||
|
@ -410,11 +459,11 @@ impl<O: Debug> ObligationForest<O> {
|
|||
}
|
||||
|
||||
impl<O> Node<O> {
|
||||
fn new(root: NodeIndex, parent: Option<NodeIndex>, obligation: O) -> Node<O> {
|
||||
fn new(tree: TreeIndex, parent: Option<NodeIndex>, obligation: O) -> Node<O> {
|
||||
Node {
|
||||
parent: parent,
|
||||
state: NodeState::Pending { obligation: obligation },
|
||||
root: root
|
||||
tree: tree,
|
||||
}
|
||||
}
|
||||
|
||||
|
|
|
@ -13,22 +13,24 @@ use super::{ObligationForest, Outcome, Error};
|
|||
#[test]
|
||||
fn push_pop() {
|
||||
let mut forest = ObligationForest::new();
|
||||
forest.push_root("A");
|
||||
forest.push_root("B");
|
||||
forest.push_root("C");
|
||||
forest.push_tree("A", "A");
|
||||
forest.push_tree("B", "B");
|
||||
forest.push_tree("C", "C");
|
||||
|
||||
// first round, B errors out, A has subtasks, and C completes, creating this:
|
||||
// A |-> A.1
|
||||
// |-> A.2
|
||||
// |-> A.3
|
||||
let Outcome { completed: ok, errors: err, .. } = forest.process_obligations(|obligation, _| {
|
||||
match *obligation {
|
||||
"A" => Ok(Some(vec!["A.1", "A.2", "A.3"])),
|
||||
"B" => Err("B is for broken"),
|
||||
"C" => Ok(Some(vec![])),
|
||||
_ => unreachable!(),
|
||||
}
|
||||
});
|
||||
let Outcome { completed: ok, errors: err, .. } =
|
||||
forest.process_obligations(|obligation, tree, _| {
|
||||
assert_eq!(obligation.chars().next(), tree.chars().next());
|
||||
match *obligation {
|
||||
"A" => Ok(Some(vec!["A.1", "A.2", "A.3"])),
|
||||
"B" => Err("B is for broken"),
|
||||
"C" => Ok(Some(vec![])),
|
||||
_ => unreachable!(),
|
||||
}
|
||||
});
|
||||
assert_eq!(ok, vec!["C"]);
|
||||
assert_eq!(err, vec![Error {error: "B is for broken",
|
||||
backtrace: vec!["B"]}]);
|
||||
|
@ -39,9 +41,10 @@ fn push_pop() {
|
|||
// |-> A.3 |-> A.3.i
|
||||
// D |-> D.1
|
||||
// |-> D.2
|
||||
forest.push_root("D");
|
||||
forest.push_tree("D", "D");
|
||||
let Outcome { completed: ok, errors: err, .. }: Outcome<&'static str, ()> =
|
||||
forest.process_obligations(|obligation, _| {
|
||||
forest.process_obligations(|obligation, tree, _| {
|
||||
assert_eq!(obligation.chars().next(), tree.chars().next());
|
||||
match *obligation {
|
||||
"A.1" => Ok(None),
|
||||
"A.2" => Ok(None),
|
||||
|
@ -58,26 +61,30 @@ fn push_pop() {
|
|||
// propagates to A.3.i, but not D.1 or D.2.
|
||||
// D |-> D.1 |-> D.1.i
|
||||
// |-> D.2 |-> D.2.i
|
||||
let Outcome { completed: ok, errors: err, .. } = forest.process_obligations(|obligation, _| {
|
||||
match *obligation {
|
||||
"A.1" => Ok(Some(vec![])),
|
||||
"A.2" => Err("A is for apple"),
|
||||
"D.1" => Ok(Some(vec!["D.1.i"])),
|
||||
"D.2" => Ok(Some(vec!["D.2.i"])),
|
||||
_ => unreachable!(),
|
||||
}
|
||||
});
|
||||
let Outcome { completed: ok, errors: err, .. } =
|
||||
forest.process_obligations(|obligation, tree, _| {
|
||||
assert_eq!(obligation.chars().next(), tree.chars().next());
|
||||
match *obligation {
|
||||
"A.1" => Ok(Some(vec![])),
|
||||
"A.2" => Err("A is for apple"),
|
||||
"D.1" => Ok(Some(vec!["D.1.i"])),
|
||||
"D.2" => Ok(Some(vec!["D.2.i"])),
|
||||
_ => unreachable!(),
|
||||
}
|
||||
});
|
||||
assert_eq!(ok, vec!["A.1"]);
|
||||
assert_eq!(err, vec![Error { error: "A is for apple",
|
||||
backtrace: vec!["A.2", "A"] }]);
|
||||
|
||||
// fourth round: error in D.1.i that should propagate to D.2.i
|
||||
let Outcome { completed: ok, errors: err, .. } = forest.process_obligations(|obligation, _| {
|
||||
match *obligation {
|
||||
"D.1.i" => Err("D is for dumb"),
|
||||
_ => panic!("unexpected obligation {:?}", obligation),
|
||||
}
|
||||
});
|
||||
let Outcome { completed: ok, errors: err, .. } =
|
||||
forest.process_obligations(|obligation, tree, _| {
|
||||
assert_eq!(obligation.chars().next(), tree.chars().next());
|
||||
match *obligation {
|
||||
"D.1.i" => Err("D is for dumb"),
|
||||
_ => panic!("unexpected obligation {:?}", obligation),
|
||||
}
|
||||
});
|
||||
assert_eq!(ok, Vec::<&'static str>::new());
|
||||
assert_eq!(err, vec![Error { error: "D is for dumb",
|
||||
backtrace: vec!["D.1.i", "D.1", "D"] }]);
|
||||
|
@ -94,10 +101,11 @@ fn push_pop() {
|
|||
#[test]
|
||||
fn success_in_grandchildren() {
|
||||
let mut forest = ObligationForest::new();
|
||||
forest.push_root("A");
|
||||
forest.push_tree("A", "A");
|
||||
|
||||
let Outcome { completed: ok, errors: err, .. } =
|
||||
forest.process_obligations::<(),_>(|obligation, _| {
|
||||
forest.process_obligations::<(),_>(|obligation, tree, _| {
|
||||
assert_eq!(obligation.chars().next(), tree.chars().next());
|
||||
match *obligation {
|
||||
"A" => Ok(Some(vec!["A.1", "A.2", "A.3"])),
|
||||
_ => unreachable!(),
|
||||
|
@ -107,7 +115,8 @@ fn success_in_grandchildren() {
|
|||
assert!(err.is_empty());
|
||||
|
||||
let Outcome { completed: ok, errors: err, .. } =
|
||||
forest.process_obligations::<(),_>(|obligation, _| {
|
||||
forest.process_obligations::<(),_>(|obligation, tree, _| {
|
||||
assert_eq!(obligation.chars().next(), tree.chars().next());
|
||||
match *obligation {
|
||||
"A.1" => Ok(Some(vec![])),
|
||||
"A.2" => Ok(Some(vec!["A.2.i", "A.2.ii"])),
|
||||
|
@ -119,7 +128,8 @@ fn success_in_grandchildren() {
|
|||
assert!(err.is_empty());
|
||||
|
||||
let Outcome { completed: ok, errors: err, .. } =
|
||||
forest.process_obligations::<(),_>(|obligation, _| {
|
||||
forest.process_obligations::<(),_>(|obligation, tree, _| {
|
||||
assert_eq!(obligation.chars().next(), tree.chars().next());
|
||||
match *obligation {
|
||||
"A.2.i" => Ok(Some(vec!["A.2.i.a"])),
|
||||
"A.2.ii" => Ok(Some(vec![])),
|
||||
|
@ -130,7 +140,8 @@ fn success_in_grandchildren() {
|
|||
assert!(err.is_empty());
|
||||
|
||||
let Outcome { completed: ok, errors: err, .. } =
|
||||
forest.process_obligations::<(),_>(|obligation, _| {
|
||||
forest.process_obligations::<(),_>(|obligation, tree, _| {
|
||||
assert_eq!(obligation.chars().next(), tree.chars().next());
|
||||
match *obligation {
|
||||
"A.2.i.a" => Ok(Some(vec![])),
|
||||
_ => unreachable!(),
|
||||
|
@ -140,7 +151,7 @@ fn success_in_grandchildren() {
|
|||
assert!(err.is_empty());
|
||||
|
||||
let Outcome { completed: ok, errors: err, .. } =
|
||||
forest.process_obligations::<(),_>(|_, _| unreachable!());
|
||||
forest.process_obligations::<(),_>(|_, _, _| unreachable!());
|
||||
assert!(ok.is_empty());
|
||||
assert!(err.is_empty());
|
||||
}
|
||||
|
@ -150,9 +161,10 @@ fn to_errors_no_throw() {
|
|||
// check that converting multiple children with common parent (A)
|
||||
// only yields one of them (and does not panic, in particular).
|
||||
let mut forest = ObligationForest::new();
|
||||
forest.push_root("A");
|
||||
forest.push_tree("A", "A");
|
||||
let Outcome { completed: ok, errors: err, .. } =
|
||||
forest.process_obligations::<(),_>(|obligation, _| {
|
||||
forest.process_obligations::<(),_>(|obligation, tree, _| {
|
||||
assert_eq!(obligation.chars().next(), tree.chars().next());
|
||||
match *obligation {
|
||||
"A" => Ok(Some(vec!["A.1", "A.2", "A.3"])),
|
||||
_ => unreachable!(),
|
||||
|
@ -168,10 +180,11 @@ fn to_errors_no_throw() {
|
|||
fn backtrace() {
|
||||
// check that converting multiple children with common parent (A)
|
||||
// only yields one of them (and does not panic, in particular).
|
||||
let mut forest: ObligationForest<&'static str> = ObligationForest::new();
|
||||
forest.push_root("A");
|
||||
let mut forest = ObligationForest::new();
|
||||
forest.push_tree("A", "A");
|
||||
let Outcome { completed: ok, errors: err, .. } =
|
||||
forest.process_obligations::<(),_>(|obligation, mut backtrace| {
|
||||
forest.process_obligations::<(),_>(|obligation, tree, mut backtrace| {
|
||||
assert_eq!(obligation.chars().next(), tree.chars().next());
|
||||
assert!(backtrace.next().is_none());
|
||||
match *obligation {
|
||||
"A" => Ok(Some(vec!["A.1"])),
|
||||
|
@ -181,7 +194,8 @@ fn backtrace() {
|
|||
assert!(ok.is_empty());
|
||||
assert!(err.is_empty());
|
||||
let Outcome { completed: ok, errors: err, .. } =
|
||||
forest.process_obligations::<(),_>(|obligation, mut backtrace| {
|
||||
forest.process_obligations::<(),_>(|obligation, tree, mut backtrace| {
|
||||
assert_eq!(obligation.chars().next(), tree.chars().next());
|
||||
assert!(backtrace.next().unwrap() == &"A");
|
||||
assert!(backtrace.next().is_none());
|
||||
match *obligation {
|
||||
|
@ -192,7 +206,8 @@ fn backtrace() {
|
|||
assert!(ok.is_empty());
|
||||
assert!(err.is_empty());
|
||||
let Outcome { completed: ok, errors: err, .. } =
|
||||
forest.process_obligations::<(),_>(|obligation, mut backtrace| {
|
||||
forest.process_obligations::<(),_>(|obligation, tree, mut backtrace| {
|
||||
assert_eq!(obligation.chars().next(), tree.chars().next());
|
||||
assert!(backtrace.next().unwrap() == &"A.1");
|
||||
assert!(backtrace.next().unwrap() == &"A");
|
||||
assert!(backtrace.next().is_none());
|
||||
|
|
|
@ -0,0 +1,28 @@
|
|||
// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
|
||||
// file at the top-level directory of this distribution and at
|
||||
// http://rust-lang.org/COPYRIGHT.
|
||||
//
|
||||
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
|
||||
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
|
||||
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
|
||||
// option. This file may not be copied, modified, or distributed
|
||||
// except according to those terms.
|
||||
|
||||
use std::u32;
|
||||
|
||||
#[derive(Copy, Clone, Debug, PartialEq, Eq)]
|
||||
pub struct TreeIndex {
|
||||
index: u32
|
||||
}
|
||||
|
||||
impl TreeIndex {
|
||||
pub fn new(value: usize) -> TreeIndex {
|
||||
assert!(value < (u32::MAX as usize));
|
||||
TreeIndex { index: value as u32 }
|
||||
}
|
||||
|
||||
pub fn get(self) -> usize {
|
||||
self.index as usize
|
||||
}
|
||||
}
|
||||
|
Loading…
Reference in New Issue