fully move dropck to mir

This commit is contained in:
lcnr 2022-06-28 22:56:32 +02:00
parent a5c6a48aee
commit 8deadfa271
16 changed files with 79 additions and 124 deletions

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@ -1,11 +1,11 @@
use itertools::{Either, Itertools};
use rustc_data_structures::fx::FxHashSet;
use rustc_middle::mir::{Body, Local};
use rustc_middle::ty::{RegionVid, TyCtxt};
use std::rc::Rc;
use rustc_mir_dataflow::impls::MaybeInitializedPlaces;
use rustc_mir_dataflow::move_paths::MoveData;
use rustc_mir_dataflow::ResultsCursor;
use std::rc::Rc;
use crate::{
constraints::OutlivesConstraintSet,
@ -46,7 +46,8 @@ pub(super) fn generate<'mir, 'tcx>(
&typeck.borrowck_context.universal_regions,
&typeck.borrowck_context.constraints.outlives_constraints,
);
let live_locals = compute_live_locals(typeck.tcx(), &free_regions, &body);
let (relevant_live_locals, boring_locals) =
compute_relevant_live_locals(typeck.tcx(), &free_regions, &body);
let facts_enabled = use_polonius || AllFacts::enabled(typeck.tcx());
let polonius_drop_used = if facts_enabled {
@ -57,48 +58,44 @@ pub(super) fn generate<'mir, 'tcx>(
None
};
if !live_locals.is_empty() || facts_enabled {
trace::trace(
typeck,
body,
elements,
flow_inits,
move_data,
live_locals,
relevant_live_locals,
boring_locals,
polonius_drop_used,
);
}
}
// The purpose of `compute_live_locals` is to define the subset of `Local`
// The purpose of `compute_relevant_live_locals` is to define the subset of `Local`
// variables for which we need to do a liveness computation. We only need
// to compute whether a variable `X` is live if that variable contains
// some region `R` in its type where `R` is not known to outlive a free
// region (i.e., where `R` may be valid for just a subset of the fn body).
fn compute_live_locals<'tcx>(
fn compute_relevant_live_locals<'tcx>(
tcx: TyCtxt<'tcx>,
free_regions: &FxHashSet<RegionVid>,
body: &Body<'tcx>,
) -> Vec<Local> {
let live_locals: Vec<Local> = body
.local_decls
.iter_enumerated()
.filter_map(|(local, local_decl)| {
) -> (Vec<Local>, Vec<Local>) {
let (boring_locals, relevant_live_locals): (Vec<_>, Vec<_>) =
body.local_decls.iter_enumerated().partition_map(|(local, local_decl)| {
if tcx.all_free_regions_meet(&local_decl.ty, |r| {
free_regions.contains(&r.to_region_vid())
}) {
None
Either::Left(local)
} else {
Some(local)
Either::Right(local)
}
})
.collect();
});
debug!("{} total variables", body.local_decls.len());
debug!("{} variables need liveness", live_locals.len());
debug!("{} variables need liveness", relevant_live_locals.len());
debug!("{} regions outlive free regions", free_regions.len());
live_locals
(relevant_live_locals, boring_locals)
}
/// Computes all regions that are (currently) known to outlive free

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@ -41,12 +41,13 @@ pub(super) fn trace<'mir, 'tcx>(
elements: &Rc<RegionValueElements>,
flow_inits: &mut ResultsCursor<'mir, 'tcx, MaybeInitializedPlaces<'mir, 'tcx>>,
move_data: &MoveData<'tcx>,
live_locals: Vec<Local>,
relevant_live_locals: Vec<Local>,
boring_locals: Vec<Local>,
polonius_drop_used: Option<Vec<(Local, Location)>>,
) {
debug!("trace()");
let local_use_map = &LocalUseMap::build(&live_locals, elements, body);
let local_use_map = &LocalUseMap::build(&relevant_live_locals, elements, body);
let cx = LivenessContext {
typeck,
@ -61,10 +62,12 @@ pub(super) fn trace<'mir, 'tcx>(
let mut results = LivenessResults::new(cx);
if let Some(drop_used) = polonius_drop_used {
results.add_extra_drop_facts(drop_used, live_locals.iter().copied().collect())
results.add_extra_drop_facts(drop_used, relevant_live_locals.iter().copied().collect())
}
results.compute_for_all_locals(live_locals);
results.compute_for_all_locals(relevant_live_locals);
results.dropck_boring_locals(boring_locals);
}
/// Contextual state for the type-liveness generator.
@ -133,8 +136,8 @@ impl<'me, 'typeck, 'flow, 'tcx> LivenessResults<'me, 'typeck, 'flow, 'tcx> {
}
}
fn compute_for_all_locals(&mut self, live_locals: Vec<Local>) {
for local in live_locals {
fn compute_for_all_locals(&mut self, relevant_live_locals: Vec<Local>) {
for local in relevant_live_locals {
self.reset_local_state();
self.add_defs_for(local);
self.compute_use_live_points_for(local);
@ -157,6 +160,24 @@ impl<'me, 'typeck, 'flow, 'tcx> LivenessResults<'me, 'typeck, 'flow, 'tcx> {
}
}
// Runs dropck for locals whose liveness isn't relevant. This is
// necessary to eagerly detect unbound recursion during drop glue computation.
fn dropck_boring_locals(&mut self, boring_locals: Vec<Local>) {
for local in boring_locals {
let local_ty = self.cx.body.local_decls[local].ty;
let drop_data = self.cx.drop_data.entry(local_ty).or_insert_with({
let typeck = &mut self.cx.typeck;
move || LivenessContext::compute_drop_data(typeck, local_ty)
});
drop_data.dropck_result.report_overflows(
self.cx.typeck.infcx.tcx,
self.cx.body.local_decls[local].source_info.span,
local_ty,
);
}
}
/// Add extra drop facts needed for Polonius.
///
/// Add facts for all locals with free regions, since regions may outlive
@ -164,12 +185,12 @@ impl<'me, 'typeck, 'flow, 'tcx> LivenessResults<'me, 'typeck, 'flow, 'tcx> {
fn add_extra_drop_facts(
&mut self,
drop_used: Vec<(Local, Location)>,
live_locals: FxHashSet<Local>,
relevant_live_locals: FxHashSet<Local>,
) {
let locations = IntervalSet::new(self.cx.elements.num_points());
for (local, location) in drop_used {
if !live_locals.contains(&local) {
if !relevant_live_locals.contains(&local) {
let local_ty = self.cx.body.local_decls[local].ty;
if local_ty.has_free_regions() {
self.cx.add_drop_live_facts_for(local, local_ty, &[location], &locations);

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@ -1825,7 +1825,8 @@ rustc_queries! {
remap_env_constness
}
/// Do not call this query directly: invoke `infcx.at().dropck_outlives()` instead.
/// Do not call this query directly:
/// invoke `DropckOutlives::new(dropped_ty)).fully_perform(typeck.infcx)` instead.
query dropck_outlives(
goal: CanonicalTyGoal<'tcx>
) -> Result<

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@ -8,8 +8,6 @@ use rustc_middle::ty::subst::SubstsRef;
use rustc_middle::ty::util::IgnoreRegions;
use rustc_middle::ty::{self, Predicate, Ty, TyCtxt};
use rustc_span::Span;
use rustc_trait_selection::traits::query::dropck_outlives::AtExt;
use rustc_trait_selection::traits::ObligationCause;
/// This function confirms that the `Drop` implementation identified by
/// `drop_impl_did` is not any more specialized than the type it is
@ -234,18 +232,14 @@ fn ensure_drop_predicates_are_implied_by_item_defn<'tcx>(
/// This function is not only checking that the dropck obligations are met for
/// the given type, but it's also currently preventing non-regular recursion in
/// types from causing stack overflows (dropck_no_diverge_on_nonregular_*.rs).
///
/// FIXME: Completely rip out dropck and regionck.
pub(crate) fn check_drop_obligations<'a, 'tcx>(
rcx: &mut RegionCtxt<'a, 'tcx>,
ty: Ty<'tcx>,
span: Span,
body_id: hir::HirId,
_rcx: &mut RegionCtxt<'a, 'tcx>,
_ty: Ty<'tcx>,
_span: Span,
_body_id: hir::HirId,
) {
debug!("check_drop_obligations typ: {:?}", ty);
let cause = &ObligationCause::misc(span, body_id);
let infer_ok = rcx.infcx.at(cause, rcx.fcx.param_env).dropck_outlives(ty);
debug!("dropck_outlives = {:#?}", infer_ok);
rcx.fcx.register_infer_ok_obligations(infer_ok);
}
// This is an implementation of the TypeRelation trait with the

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@ -23,5 +23,4 @@ enum FingerTree<T:'static> {
fn main() {
let ft = //~ ERROR overflow while adding drop-check rules for FingerTree
FingerTree::Single(1);
//~^ ERROR overflow while adding drop-check rules for FingerTree
}

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@ -6,13 +6,5 @@ LL | let ft =
|
= note: overflowed on FingerTree<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<i32>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
error[E0320]: overflow while adding drop-check rules for FingerTree<i32>
--> $DIR/dropck_no_diverge_on_nonregular_1.rs:25:9
|
LL | FingerTree::Single(1);
| ^^^^^^^^^^^^^^^^^^^^^
|
= note: overflowed on FingerTree<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<i32>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
error: aborting due to 2 previous errors
error: aborting due to previous error

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@ -22,5 +22,4 @@ enum FingerTree<T:'static> {
fn main() {
let ft = //~ ERROR overflow while adding drop-check rules for FingerTree
FingerTree::Single(1);
//~^ ERROR overflow while adding drop-check rules for FingerTree
}

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@ -6,13 +6,5 @@ LL | let ft =
|
= note: overflowed on FingerTree<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<i32>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
error[E0320]: overflow while adding drop-check rules for FingerTree<i32>
--> $DIR/dropck_no_diverge_on_nonregular_2.rs:24:9
|
LL | FingerTree::Single(1);
| ^^^^^^^^^^^^^^^^^^^^^
|
= note: overflowed on FingerTree<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<i32>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
error: aborting due to 2 previous errors
error: aborting due to previous error

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@ -31,6 +31,5 @@ enum Wrapper<T:'static> {
fn main() {
let w = //~ ERROR overflow while adding drop-check rules for Option
Some(Wrapper::Simple::<u32>);
//~^ ERROR overflow while adding drop-check rules for Option
//~| ERROR overflow while adding drop-check rules for Wrapper
//~^ ERROR overflow while adding drop-check rules for Wrapper
}

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@ -6,14 +6,6 @@ LL | let w =
|
= note: overflowed on FingerTree<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<u32>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
error[E0320]: overflow while adding drop-check rules for Option<Wrapper<u32>>
--> $DIR/dropck_no_diverge_on_nonregular_3.rs:33:9
|
LL | Some(Wrapper::Simple::<u32>);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: overflowed on FingerTree<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<u32>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
error[E0320]: overflow while adding drop-check rules for Wrapper<u32>
--> $DIR/dropck_no_diverge_on_nonregular_3.rs:33:14
|
@ -22,5 +14,5 @@ LL | Some(Wrapper::Simple::<u32>);
|
= note: overflowed on FingerTree<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<Node<u32>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
error: aborting due to 3 previous errors
error: aborting due to 2 previous errors

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@ -1,6 +1,5 @@
struct Take(Take);
//~^ ERROR has infinite size
//~| ERROR cycle detected
// check that we don't hang trying to find the tail of a recursive struct (#79437)
fn foo() -> Take {

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@ -11,16 +11,6 @@ help: insert some indirection (e.g., a `Box`, `Rc`, or `&`) to make `Take` repre
LL | struct Take(Box<Take>);
| ++++ +
error[E0391]: cycle detected when computing drop-check constraints for `Take`
--> $DIR/infinite-struct.rs:1:1
|
LL | struct Take(Take);
| ^^^^^^^^^^^
|
= note: ...which immediately requires computing drop-check constraints for `Take` again
= note: cycle used when computing dropck types for `Canonical { max_universe: U0, variables: [], value: ParamEnvAnd { param_env: ParamEnv { caller_bounds: [], reveal: UserFacing, constness: NotConst }, value: Take } }`
error: aborting due to previous error
error: aborting due to 2 previous errors
Some errors have detailed explanations: E0072, E0391.
For more information about an error, try `rustc --explain E0072`.
For more information about this error, try `rustc --explain E0072`.

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@ -1,5 +1,4 @@
enum MList { Cons(isize, MList), Nil }
//~^ ERROR recursive type `MList` has infinite size
//~| ERROR cycle detected when computing drop-check constraints for `MList`
fn main() { let a = MList::Cons(10, MList::Cons(11, MList::Nil)); }

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@ -11,16 +11,6 @@ help: insert some indirection (e.g., a `Box`, `Rc`, or `&`) to make `MList` repr
LL | enum MList { Cons(isize, Box<MList>), Nil }
| ++++ +
error[E0391]: cycle detected when computing drop-check constraints for `MList`
--> $DIR/infinite-tag-type-recursion.rs:1:1
|
LL | enum MList { Cons(isize, MList), Nil }
| ^^^^^^^^^^
|
= note: ...which immediately requires computing drop-check constraints for `MList` again
= note: cycle used when computing dropck types for `Canonical { max_universe: U0, variables: [], value: ParamEnvAnd { param_env: ParamEnv { caller_bounds: [], reveal: UserFacing, constness: NotConst }, value: MList } }`
error: aborting due to previous error
error: aborting due to 2 previous errors
Some errors have detailed explanations: E0072, E0391.
For more information about an error, try `rustc --explain E0072`.
For more information about this error, try `rustc --explain E0072`.

View File

@ -1,18 +1,14 @@
// Dropck shouldn't hit a recursion limit from checking `S<u32>` since it has
// no free regions or type parameters.
// Codegen however, has to error for the infinitely many `drop_in_place`
// functions it has been asked to create.
// build-fail
// normalize-stderr-test: ".nll/" -> "/"
// compile-flags: -Zmir-opt-level=0
// `S` is infinitely recursing so it's not possible to generate a finite
// drop impl (ignoring polymorphization).
//
// Dropck should therefore detect that this is the case and eagerly error.
struct S<T> {
t: T,
s: Box<S<fn(u: T)>>,
}
fn f(x: S<u32>) {}
fn f(x: S<u32>) {} //~ ERROR overflow while adding drop-check rules for S<u32>
fn main() {
// Force instantiation.

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@ -1,15 +1,10 @@
error: reached the recursion limit while instantiating `std::ptr::drop_in_place::<S<fn(f...)))))))))))))))))))))))))))))>))`
--> $SRC_DIR/core/src/ptr/mod.rs:LL:COL
error[E0320]: overflow while adding drop-check rules for S<u32>
--> $DIR/issue-38591-non-regular-dropck-recursion.rs:11:6
|
LL | pub unsafe fn drop_in_place<T: ?Sized>(to_drop: *mut T) {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
LL | fn f(x: S<u32>) {}
| ^
|
note: `std::ptr::drop_in_place` defined here
--> $SRC_DIR/core/src/ptr/mod.rs:LL:COL
|
LL | pub unsafe fn drop_in_place<T: ?Sized>(to_drop: *mut T) {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
= note: the full type name has been written to '$TEST_BUILD_DIR/recursion/issue-38591-non-regular-dropck-recursion/issue-38591-non-regular-dropck-recursion.long-type.txt'
= note: overflowed on S<fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(fn(u32)))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))>
error: aborting due to previous error