Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Revert lazy TAIT PR #93893

Merged
merged 3 commits into from
Feb 11, 2022
Merged

Revert lazy TAIT PR #93893

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
7a71b7a
Revert "Fix regression from lazy opaque types"
oli-obk Feb 11, 2022
2d8b8f3
Revert "Auto merge of #92306 - Aaron1011:opaque-type-op, r=oli-obk"
oli-obk Feb 11, 2022
d54195d
Revert "Auto merge of #92007 - oli-obk:lazy_tait2, r=nikomatsakis"
oli-obk Feb 11, 2022
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
The table of contents is too big for display.
Diff view
Diff view
  •  
  •  
  •  
108 changes: 21 additions & 87 deletions compiler/rustc_borrowck/src/diagnostics/bound_region_errors.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2,13 +2,9 @@ use rustc_errors::DiagnosticBuilder;
use rustc_infer::infer::canonical::Canonical;
use rustc_infer::infer::error_reporting::nice_region_error::NiceRegionError;
use rustc_infer::infer::region_constraints::Constraint;
use rustc_infer::infer::region_constraints::RegionConstraintData;
use rustc_infer::infer::RegionVariableOrigin;
use rustc_infer::infer::{InferCtxt, RegionResolutionError, SubregionOrigin, TyCtxtInferExt as _};
use rustc_infer::traits::{Normalized, ObligationCause, TraitEngine, TraitEngineExt};
use rustc_middle::ty::error::TypeError;
use rustc_middle::ty::RegionVid;
use rustc_middle::ty::UniverseIndex;
use rustc_middle::ty::{self, Ty, TyCtxt, TypeFoldable};
use rustc_span::Span;
use rustc_trait_selection::traits::query::type_op;
Expand Down Expand Up @@ -82,15 +78,6 @@ crate trait ToUniverseInfo<'tcx> {
fn to_universe_info(self, base_universe: ty::UniverseIndex) -> UniverseInfo<'tcx>;
}

impl<'tcx> ToUniverseInfo<'tcx> for crate::type_check::InstantiateOpaqueType<'tcx> {
fn to_universe_info(self, base_universe: ty::UniverseIndex) -> UniverseInfo<'tcx> {
UniverseInfo(UniverseInfoInner::TypeOp(Rc::new(crate::type_check::InstantiateOpaqueType {
base_universe: Some(base_universe),
..self
})))
}
}

impl<'tcx> ToUniverseInfo<'tcx>
for Canonical<'tcx, ty::ParamEnvAnd<'tcx, type_op::prove_predicate::ProvePredicate<'tcx>>>
{
Expand Down Expand Up @@ -131,12 +118,6 @@ impl<'tcx, F, G> ToUniverseInfo<'tcx> for Canonical<'tcx, type_op::custom::Custo
}
}

impl<'tcx> ToUniverseInfo<'tcx> for ! {
fn to_universe_info(self, _base_universe: ty::UniverseIndex) -> UniverseInfo<'tcx> {
self
}
}

#[allow(unused_lifetimes)]
trait TypeOpInfo<'tcx> {
/// Returns an error to be reported if rerunning the type op fails to
Expand All @@ -147,7 +128,7 @@ trait TypeOpInfo<'tcx> {

fn nice_error(
&self,
mbcx: &mut MirBorrowckCtxt<'_, 'tcx>,
tcx: TyCtxt<'tcx>,
cause: ObligationCause<'tcx>,
placeholder_region: ty::Region<'tcx>,
error_region: Option<ty::Region<'tcx>>,
Expand Down Expand Up @@ -194,7 +175,7 @@ trait TypeOpInfo<'tcx> {
debug!(?placeholder_region);

let span = cause.span;
let nice_error = self.nice_error(mbcx, cause, placeholder_region, error_region);
let nice_error = self.nice_error(tcx, cause, placeholder_region, error_region);

if let Some(nice_error) = nice_error {
nice_error.buffer(&mut mbcx.errors_buffer);
Expand Down Expand Up @@ -223,16 +204,16 @@ impl<'tcx> TypeOpInfo<'tcx> for PredicateQuery<'tcx> {

fn nice_error(
&self,
mbcx: &mut MirBorrowckCtxt<'_, 'tcx>,
tcx: TyCtxt<'tcx>,
cause: ObligationCause<'tcx>,
placeholder_region: ty::Region<'tcx>,
error_region: Option<ty::Region<'tcx>>,
) -> Option<DiagnosticBuilder<'tcx>> {
mbcx.infcx.tcx.infer_ctxt().enter_with_canonical(
tcx.infer_ctxt().enter_with_canonical(
cause.span,
&self.canonical_query,
|ref infcx, key, _| {
let mut fulfill_cx = <dyn TraitEngine<'_>>::new(infcx.tcx);
let mut fulfill_cx = <dyn TraitEngine<'_>>::new(tcx);
type_op_prove_predicate_with_cause(infcx, &mut *fulfill_cx, key, cause);
try_extract_error_from_fulfill_cx(
fulfill_cx,
Expand Down Expand Up @@ -266,16 +247,16 @@ where

fn nice_error(
&self,
mbcx: &mut MirBorrowckCtxt<'_, 'tcx>,
tcx: TyCtxt<'tcx>,
cause: ObligationCause<'tcx>,
placeholder_region: ty::Region<'tcx>,
error_region: Option<ty::Region<'tcx>>,
) -> Option<DiagnosticBuilder<'tcx>> {
mbcx.infcx.tcx.infer_ctxt().enter_with_canonical(
tcx.infer_ctxt().enter_with_canonical(
cause.span,
&self.canonical_query,
|ref infcx, key, _| {
let mut fulfill_cx = <dyn TraitEngine<'_>>::new(infcx.tcx);
let mut fulfill_cx = <dyn TraitEngine<'_>>::new(tcx);

let mut selcx = SelectionContext::new(infcx);

Expand Down Expand Up @@ -323,16 +304,16 @@ impl<'tcx> TypeOpInfo<'tcx> for AscribeUserTypeQuery<'tcx> {

fn nice_error(
&self,
mbcx: &mut MirBorrowckCtxt<'_, 'tcx>,
tcx: TyCtxt<'tcx>,
cause: ObligationCause<'tcx>,
placeholder_region: ty::Region<'tcx>,
error_region: Option<ty::Region<'tcx>>,
) -> Option<DiagnosticBuilder<'tcx>> {
mbcx.infcx.tcx.infer_ctxt().enter_with_canonical(
tcx.infer_ctxt().enter_with_canonical(
cause.span,
&self.canonical_query,
|ref infcx, key, _| {
let mut fulfill_cx = <dyn TraitEngine<'_>>::new(infcx.tcx);
let mut fulfill_cx = <dyn TraitEngine<'_>>::new(tcx);
type_op_ascribe_user_type_with_span(infcx, &mut *fulfill_cx, key, Some(cause.span))
.ok()?;
try_extract_error_from_fulfill_cx(
Expand All @@ -346,90 +327,43 @@ impl<'tcx> TypeOpInfo<'tcx> for AscribeUserTypeQuery<'tcx> {
}
}

impl<'tcx> TypeOpInfo<'tcx> for crate::type_check::InstantiateOpaqueType<'tcx> {
fn fallback_error(&self, tcx: TyCtxt<'tcx>, span: Span) -> DiagnosticBuilder<'tcx> {
// FIXME: This error message isn't great, but it doesn't show up in the existing UI tests,
// and is only the fallback when the nice error fails. Consider improving this some more.
tcx.sess.struct_span_err(span, "higher-ranked lifetime error for opaque type!")
}

fn base_universe(&self) -> ty::UniverseIndex {
self.base_universe.unwrap()
}

fn nice_error(
&self,
mbcx: &mut MirBorrowckCtxt<'_, 'tcx>,
_cause: ObligationCause<'tcx>,
placeholder_region: ty::Region<'tcx>,
error_region: Option<ty::Region<'tcx>>,
) -> Option<DiagnosticBuilder<'tcx>> {
try_extract_error_from_region_constraints(
mbcx.infcx,
placeholder_region,
error_region,
self.region_constraints.as_ref().unwrap(),
// We're using the original `InferCtxt` that we
// started MIR borrowchecking with, so the region
// constraints have already been taken. Use the data from
// our `mbcx` instead.
|vid| mbcx.regioncx.var_infos[vid].origin,
|vid| mbcx.regioncx.var_infos[vid].universe,
)
}
}

#[instrument(skip(fulfill_cx, infcx), level = "debug")]
fn try_extract_error_from_fulfill_cx<'tcx>(
mut fulfill_cx: Box<dyn TraitEngine<'tcx> + 'tcx>,
infcx: &InferCtxt<'_, 'tcx>,
placeholder_region: ty::Region<'tcx>,
error_region: Option<ty::Region<'tcx>>,
) -> Option<DiagnosticBuilder<'tcx>> {
let tcx = infcx.tcx;

// We generally shouldn't have errors here because the query was
// already run, but there's no point using `delay_span_bug`
// when we're going to emit an error here anyway.
let _errors = fulfill_cx.select_all_or_error(infcx);
let region_constraints = infcx.with_region_constraints(|r| r.clone());
try_extract_error_from_region_constraints(
infcx,
placeholder_region,
error_region,
&region_constraints,
|vid| infcx.region_var_origin(vid),
|vid| infcx.universe_of_region(infcx.tcx.mk_region(ty::ReVar(vid))),
)
}

fn try_extract_error_from_region_constraints<'tcx>(
infcx: &InferCtxt<'_, 'tcx>,
placeholder_region: ty::Region<'tcx>,
error_region: Option<ty::Region<'tcx>>,
region_constraints: &RegionConstraintData<'tcx>,
mut region_var_origin: impl FnMut(RegionVid) -> RegionVariableOrigin,
mut universe_of_region: impl FnMut(RegionVid) -> UniverseIndex,
) -> Option<DiagnosticBuilder<'tcx>> {
let (sub_region, cause) =
let (sub_region, cause) = infcx.with_region_constraints(|region_constraints| {
debug!("{:#?}", region_constraints);
region_constraints.constraints.iter().find_map(|(constraint, cause)| {
match *constraint {
Constraint::RegSubReg(sub, sup) if sup == placeholder_region && sup != sub => {
Some((sub, cause.clone()))
}
// FIXME: Should this check the universe of the var?
Constraint::VarSubReg(vid, sup) if sup == placeholder_region => {
Some((infcx.tcx.mk_region(ty::ReVar(vid)), cause.clone()))
Some((tcx.mk_region(ty::ReVar(vid)), cause.clone()))
}
_ => None,
}
})?;
})
})?;

debug!(?sub_region, "cause = {:#?}", cause);
let nice_error = match (error_region, sub_region) {
(Some(error_region), &ty::ReVar(vid)) => NiceRegionError::new(
infcx,
RegionResolutionError::SubSupConflict(
vid,
region_var_origin(vid),
infcx.region_var_origin(vid),
cause.clone(),
error_region,
cause.clone(),
Expand All @@ -446,8 +380,8 @@ fn try_extract_error_from_region_constraints<'tcx>(
infcx,
RegionResolutionError::UpperBoundUniverseConflict(
vid,
region_var_origin(vid),
universe_of_region(vid),
infcx.region_var_origin(vid),
infcx.universe_of_region(sub_region),
cause.clone(),
placeholder_region,
),
Expand Down
6 changes: 2 additions & 4 deletions compiler/rustc_borrowck/src/lib.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -5,7 +5,6 @@
#![feature(crate_visibility_modifier)]
#![feature(let_else)]
#![feature(min_specialization)]
#![feature(never_type)]
#![feature(stmt_expr_attributes)]
#![feature(trusted_step)]
#![feature(try_blocks)]
Expand Down Expand Up @@ -125,9 +124,8 @@ fn mir_borrowck<'tcx>(
) -> &'tcx BorrowCheckResult<'tcx> {
let (input_body, promoted) = tcx.mir_promoted(def);
debug!("run query mir_borrowck: {}", tcx.def_path_str(def.did.to_def_id()));
let hir_owner = tcx.hir().local_def_id_to_hir_id(def.did).owner;

let opt_closure_req = tcx.infer_ctxt().with_opaque_type_inference(hir_owner).enter(|infcx| {
let opt_closure_req = tcx.infer_ctxt().with_opaque_type_inference(def.did).enter(|infcx| {
let input_body: &Body<'_> = &input_body.borrow();
let promoted: &IndexVec<_, _> = &promoted.borrow();
do_mir_borrowck(&infcx, input_body, promoted, false).0
Expand All @@ -142,7 +140,7 @@ fn mir_borrowck<'tcx>(
/// If `return_body_with_facts` is true, then return the body with non-erased
/// region ids on which the borrow checking was performed together with Polonius
/// facts.
#[instrument(skip(infcx, input_body, input_promoted), fields(id=?input_body.source.with_opt_param().as_local().unwrap()), level = "debug")]
#[instrument(skip(infcx, input_body, input_promoted), level = "debug")]
fn do_mir_borrowck<'a, 'tcx>(
infcx: &InferCtxt<'a, 'tcx>,
input_body: &Body<'tcx>,
Expand Down
4 changes: 1 addition & 3 deletions compiler/rustc_borrowck/src/region_infer/mod.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -44,7 +44,6 @@ mod reverse_sccs;
pub mod values;

pub struct RegionInferenceContext<'tcx> {
pub var_infos: VarInfos,
/// Contains the definition for every region variable. Region
/// variables are identified by their index (`RegionVid`). The
/// definition contains information about where the region came
Expand Down Expand Up @@ -267,7 +266,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
) -> Self {
// Create a RegionDefinition for each inference variable.
let definitions: IndexVec<_, _> = var_infos
.iter()
.into_iter()
.map(|info| RegionDefinition::new(info.universe, info.origin))
.collect();

Expand All @@ -292,7 +291,6 @@ impl<'tcx> RegionInferenceContext<'tcx> {
Rc::new(member_constraints_in.into_mapped(|r| constraint_sccs.scc(r)));

let mut result = Self {
var_infos,
definitions,
liveness_constraints,
constraints,
Expand Down
58 changes: 20 additions & 38 deletions compiler/rustc_borrowck/src/region_infer/opaque_types.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,6 +1,7 @@
use rustc_data_structures::fx::FxHashMap;
use rustc_data_structures::vec_map::VecMap;
use rustc_hir::OpaqueTyOrigin;
use rustc_infer::infer::opaque_types::OpaqueTypeDecl;
use rustc_infer::infer::InferCtxt;
use rustc_middle::ty::subst::GenericArgKind;
use rustc_middle::ty::{self, OpaqueTypeKey, Ty, TyCtxt, TypeFoldable};
Expand Down Expand Up @@ -53,44 +54,27 @@ impl<'tcx> RegionInferenceContext<'tcx> {
pub(crate) fn infer_opaque_types(
&self,
infcx: &InferCtxt<'_, 'tcx>,
opaque_ty_decls: VecMap<OpaqueTypeKey<'tcx>, (Ty<'tcx>, Span, OpaqueTyOrigin)>,
opaque_ty_decls: VecMap<OpaqueTypeKey<'tcx>, OpaqueTypeDecl<'tcx>>,
span: Span,
) -> VecMap<OpaqueTypeKey<'tcx>, Ty<'tcx>> {
opaque_ty_decls
.into_iter()
.map(|(opaque_type_key, (concrete_type, decl_span, origin))| {
.filter_map(|(opaque_type_key, decl)| {
let substs = opaque_type_key.substs;
// FIXME: why are the spans in decl_span often DUMMY_SP?
let span = decl_span.substitute_dummy(span);
let concrete_type = decl.concrete_ty;
debug!(?concrete_type, ?substs);

let mut subst_regions = vec![self.universal_regions.fr_static];
let universal_substs = infcx.tcx.fold_regions(substs, &mut false, |region, _| {
if let ty::RePlaceholder(..) = region {
// Higher kinded regions don't need remapping, they don't refer to anything outside of this the substs.
return region;
}
let vid = self.to_region_vid(region);
trace!(?vid);
let scc = self.constraint_sccs.scc(vid);
trace!(?scc);
match self.scc_values.universal_regions_outlived_by(scc).find_map(|lb| {
self.eval_equal(vid, lb).then_some(self.definitions[lb].external_name?)
}) {
Some(region) => {
let vid = self.universal_regions.to_region_vid(region);
subst_regions.push(vid);
region
}
None => {
subst_regions.push(vid);
infcx.tcx.sess.delay_span_bug(
span,
"opaque type with non-universal region substs",
);
infcx.tcx.lifetimes.re_static
}
}
let vid = self.universal_regions.to_region_vid(region);
subst_regions.push(vid);
self.definitions[vid].external_name.unwrap_or_else(|| {
infcx
.tcx
.sess
.delay_span_bug(span, "opaque type with non-universal region substs");
infcx.tcx.lifetimes.re_static
})
});

subst_regions.sort();
Expand All @@ -116,14 +100,12 @@ impl<'tcx> RegionInferenceContext<'tcx> {
span,
);

(
check_opaque_type_parameter_valid(
infcx.tcx,
opaque_type_key,
if check_opaque_type_parameter_valid(infcx.tcx, opaque_type_key, origin, span) {
remapped_type
} else {
infcx.tcx.ty_error()
},
OpaqueTypeDecl { concrete_ty: remapped_type, ..decl },
)
.then_some((opaque_type_key, remapped_type))
})
.collect()
}
Expand Down Expand Up @@ -167,10 +149,9 @@ impl<'tcx> RegionInferenceContext<'tcx> {
fn check_opaque_type_parameter_valid(
tcx: TyCtxt<'_>,
opaque_type_key: OpaqueTypeKey<'_>,
origin: OpaqueTyOrigin,
span: Span,
decl: OpaqueTypeDecl<'_>,
) -> bool {
match origin {
match decl.origin {
// No need to check return position impl trait (RPIT)
// because for type and const parameters they are correct
// by construction: we convert
Expand All @@ -196,6 +177,7 @@ fn check_opaque_type_parameter_valid(
// Check these
OpaqueTyOrigin::TyAlias => {}
}
let span = decl.definition_span;
let opaque_generics = tcx.generics_of(opaque_type_key.def_id);
let mut seen_params: FxHashMap<_, Vec<_>> = FxHashMap::default();
for (i, arg) in opaque_type_key.substs.iter().enumerate() {
Expand Down
Loading