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Structurally resolve projections (but actually) in the new solver #108833

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b9fe8a5
Filter nested obligations during HIR coercion
compiler-errors Mar 6, 2023
f11baaa
Properly structurally resolve type for HIR and MIR cast checks
compiler-errors Mar 6, 2023
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85 changes: 60 additions & 25 deletions compiler/rustc_borrowck/src/type_check/mod.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -38,11 +38,13 @@ use rustc_middle::ty::{
use rustc_span::def_id::CRATE_DEF_ID;
use rustc_span::{Span, DUMMY_SP};
use rustc_target::abi::VariantIdx;
use rustc_trait_selection::traits::query::evaluate_obligation::InferCtxtExt;
use rustc_trait_selection::traits::query::type_op::custom::scrape_region_constraints;
use rustc_trait_selection::traits::query::type_op::custom::CustomTypeOp;
use rustc_trait_selection::traits::query::type_op::{TypeOp, TypeOpOutput};
use rustc_trait_selection::traits::query::Fallible;
use rustc_trait_selection::traits::PredicateObligation;
use rustc_trait_selection::traits::{fully_solve_obligation, Obligation, ObligationCause};

use rustc_mir_dataflow::impls::MaybeInitializedPlaces;
use rustc_mir_dataflow::move_paths::MoveData;
Expand Down Expand Up @@ -1154,6 +1156,31 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
self.infcx.tcx
}

fn structurally_resolved_ty(&self, ty: Ty<'tcx>) -> Ty<'tcx> {
if self.tcx().trait_solver_next() && let ty::Alias(ty::Projection, projection_ty) = *ty.kind() {
let new_infer_ty = self.infcx.next_ty_var(TypeVariableOrigin {
kind: TypeVariableOriginKind::NormalizeProjectionType,
span: DUMMY_SP,
});
let obligation = Obligation::new(
self.tcx(),
ObligationCause::dummy(),
self.param_env,
ty::Binder::dummy(ty::ProjectionPredicate {
projection_ty,
term: new_infer_ty.into(),
}),
);

if self.infcx.predicate_may_hold(&obligation) {
fully_solve_obligation(&self.infcx, obligation);
return self.infcx.resolve_vars_if_possible(new_infer_ty);
}
}

ty
}

#[instrument(skip(self, body, location), level = "debug")]
fn check_stmt(&mut self, body: &Body<'tcx>, stmt: &Statement<'tcx>, location: Location) {
let tcx = self.tcx();
Expand Down Expand Up @@ -1871,6 +1898,13 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
Rvalue::Cast(cast_kind, op, ty) => {
self.check_operand(op, location);

let structurally_resolved_cast_tys = || {
(
self.structurally_resolved_ty(op.ty(body, tcx)),
self.structurally_resolved_ty(*ty),
)
};

match cast_kind {
CastKind::Pointer(PointerCast::ReifyFnPointer) => {
let fn_sig = op.ty(body, tcx).fn_sig(tcx);
Expand Down Expand Up @@ -1902,7 +1936,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
}

CastKind::Pointer(PointerCast::ClosureFnPointer(unsafety)) => {
let sig = match op.ty(body, tcx).kind() {
let sig = match self.structurally_resolved_ty(op.ty(body, tcx)).kind() {
ty::Closure(_, substs) => substs.as_closure().sig(),
_ => bug!(),
};
Expand Down Expand Up @@ -1971,10 +2005,11 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
// get the constraints from the target type (`dyn* Clone`)
//
// apply them to prove that the source type `Foo` implements `Clone` etc
let (existential_predicates, region) = match ty.kind() {
Dynamic(predicates, region, ty::DynStar) => (predicates, region),
_ => panic!("Invalid dyn* cast_ty"),
};
let (existential_predicates, region) =
match self.structurally_resolved_ty(*ty).kind() {
Dynamic(predicates, region, ty::DynStar) => (predicates, region),
_ => panic!("Invalid dyn* cast_ty"),
};

let self_ty = op.ty(body, tcx);

Expand All @@ -2001,7 +2036,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
let ty::RawPtr(ty::TypeAndMut {
ty: ty_from,
mutbl: hir::Mutability::Mut,
}) = op.ty(body, tcx).kind() else {
}) = self.structurally_resolved_ty(op.ty(body, tcx)).kind() else {
span_mirbug!(
self,
rvalue,
Expand All @@ -2013,7 +2048,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
let ty::RawPtr(ty::TypeAndMut {
ty: ty_to,
mutbl: hir::Mutability::Not,
}) = ty.kind() else {
}) = self.structurally_resolved_ty(*ty).kind() else {
span_mirbug!(
self,
rvalue,
Expand Down Expand Up @@ -2042,7 +2077,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
CastKind::Pointer(PointerCast::ArrayToPointer) => {
let ty_from = op.ty(body, tcx);

let opt_ty_elem_mut = match ty_from.kind() {
let opt_ty_elem_mut = match self.structurally_resolved_ty(ty_from).kind() {
ty::RawPtr(ty::TypeAndMut { mutbl: array_mut, ty: array_ty }) => {
match array_ty.kind() {
ty::Array(ty_elem, _) => Some((ty_elem, *array_mut)),
Expand All @@ -2062,7 +2097,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
return;
};

let (ty_to, ty_to_mut) = match ty.kind() {
let (ty_to, ty_to_mut) = match self.structurally_resolved_ty(*ty).kind() {
ty::RawPtr(ty::TypeAndMut { mutbl: ty_to_mut, ty: ty_to }) => {
(ty_to, *ty_to_mut)
}
Expand Down Expand Up @@ -2106,9 +2141,9 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
}

CastKind::PointerExposeAddress => {
let ty_from = op.ty(body, tcx);
let (ty_from, ty) = structurally_resolved_cast_tys();
let cast_ty_from = CastTy::from_ty(ty_from);
let cast_ty_to = CastTy::from_ty(*ty);
let cast_ty_to = CastTy::from_ty(ty);
match (cast_ty_from, cast_ty_to) {
(Some(CastTy::Ptr(_) | CastTy::FnPtr), Some(CastTy::Int(_))) => (),
_ => {
Expand All @@ -2124,9 +2159,9 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
}

CastKind::PointerFromExposedAddress => {
let ty_from = op.ty(body, tcx);
let (ty_from, ty) = structurally_resolved_cast_tys();
let cast_ty_from = CastTy::from_ty(ty_from);
let cast_ty_to = CastTy::from_ty(*ty);
let cast_ty_to = CastTy::from_ty(ty);
match (cast_ty_from, cast_ty_to) {
(Some(CastTy::Int(_)), Some(CastTy::Ptr(_))) => (),
_ => {
Expand All @@ -2141,9 +2176,9 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
}
}
CastKind::IntToInt => {
let ty_from = op.ty(body, tcx);
let (ty_from, ty) = structurally_resolved_cast_tys();
let cast_ty_from = CastTy::from_ty(ty_from);
let cast_ty_to = CastTy::from_ty(*ty);
let cast_ty_to = CastTy::from_ty(ty);
match (cast_ty_from, cast_ty_to) {
(Some(CastTy::Int(_)), Some(CastTy::Int(_))) => (),
_ => {
Expand All @@ -2158,9 +2193,9 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
}
}
CastKind::IntToFloat => {
let ty_from = op.ty(body, tcx);
let (ty_from, ty) = structurally_resolved_cast_tys();
let cast_ty_from = CastTy::from_ty(ty_from);
let cast_ty_to = CastTy::from_ty(*ty);
let cast_ty_to = CastTy::from_ty(ty);
match (cast_ty_from, cast_ty_to) {
(Some(CastTy::Int(_)), Some(CastTy::Float)) => (),
_ => {
Expand All @@ -2175,9 +2210,9 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
}
}
CastKind::FloatToInt => {
let ty_from = op.ty(body, tcx);
let (ty_from, ty) = structurally_resolved_cast_tys();
let cast_ty_from = CastTy::from_ty(ty_from);
let cast_ty_to = CastTy::from_ty(*ty);
let cast_ty_to = CastTy::from_ty(ty);
match (cast_ty_from, cast_ty_to) {
(Some(CastTy::Float), Some(CastTy::Int(_))) => (),
_ => {
Expand All @@ -2192,9 +2227,9 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
}
}
CastKind::FloatToFloat => {
let ty_from = op.ty(body, tcx);
let (ty_from, ty) = structurally_resolved_cast_tys();
let cast_ty_from = CastTy::from_ty(ty_from);
let cast_ty_to = CastTy::from_ty(*ty);
let cast_ty_to = CastTy::from_ty(ty);
match (cast_ty_from, cast_ty_to) {
(Some(CastTy::Float), Some(CastTy::Float)) => (),
_ => {
Expand All @@ -2209,9 +2244,9 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
}
}
CastKind::FnPtrToPtr => {
let ty_from = op.ty(body, tcx);
let (ty_from, ty) = structurally_resolved_cast_tys();
let cast_ty_from = CastTy::from_ty(ty_from);
let cast_ty_to = CastTy::from_ty(*ty);
let cast_ty_to = CastTy::from_ty(ty);
match (cast_ty_from, cast_ty_to) {
(Some(CastTy::FnPtr), Some(CastTy::Ptr(_))) => (),
_ => {
Expand All @@ -2226,9 +2261,9 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
}
}
CastKind::PtrToPtr => {
let ty_from = op.ty(body, tcx);
let (ty_from, ty) = structurally_resolved_cast_tys();
let cast_ty_from = CastTy::from_ty(ty_from);
let cast_ty_to = CastTy::from_ty(*ty);
let cast_ty_to = CastTy::from_ty(ty);
match (cast_ty_from, cast_ty_to) {
(Some(CastTy::Ptr(_)), Some(CastTy::Ptr(_))) => (),
_ => {
Expand Down
13 changes: 12 additions & 1 deletion compiler/rustc_hir_typeck/src/coercion.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -62,6 +62,7 @@ use rustc_span::{self, BytePos, DesugaringKind, Span};
use rustc_target::spec::abi::Abi;
use rustc_trait_selection::infer::InferCtxtExt as _;
use rustc_trait_selection::traits::error_reporting::TypeErrCtxtExt as _;
use rustc_trait_selection::traits::query::evaluate_obligation::InferCtxtExt;
use rustc_trait_selection::traits::{
self, NormalizeExt, ObligationCause, ObligationCauseCode, ObligationCtxt,
};
Expand Down Expand Up @@ -144,12 +145,22 @@ impl<'f, 'tcx> Coerce<'f, 'tcx> {
debug!("unify(a: {:?}, b: {:?}, use_lub: {})", a, b, self.use_lub);
self.commit_if_ok(|_| {
let at = self.at(&self.cause, self.fcx.param_env).define_opaque_types(true);
if self.use_lub {
let result = if self.use_lub {
at.lub(b, a)
} else {
at.sup(b, a)
.map(|InferOk { value: (), obligations }| InferOk { value: a, obligations })
}?;

if self.tcx.trait_solver_next() {
for obligation in &result.obligations {
if !self.predicate_may_hold(obligation) {
return Err(TypeError::Mismatch);
}
}
}

Ok(result)
})
}

Expand Down
24 changes: 23 additions & 1 deletion compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -19,6 +19,7 @@ use rustc_hir_analysis::astconv::{
};
use rustc_infer::infer::canonical::{Canonical, OriginalQueryValues, QueryResponse};
use rustc_infer::infer::error_reporting::TypeAnnotationNeeded::E0282;
use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
use rustc_infer::infer::InferResult;
use rustc_middle::ty::adjustment::{Adjust, Adjustment, AutoBorrow, AutoBorrowMutability};
use rustc_middle::ty::error::TypeError;
Expand All @@ -34,6 +35,7 @@ use rustc_span::hygiene::DesugaringKind;
use rustc_span::symbol::{kw, sym, Ident};
use rustc_span::Span;
use rustc_trait_selection::traits::error_reporting::TypeErrCtxtExt as _;
use rustc_trait_selection::traits::query::evaluate_obligation::InferCtxtExt;
use rustc_trait_selection::traits::{self, NormalizeExt, ObligationCauseCode, ObligationCtxt};

use std::collections::hash_map::Entry;
Expand Down Expand Up @@ -1408,7 +1410,27 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
/// Resolves `typ` by a single level if `typ` is a type variable.
/// If no resolution is possible, then an error is reported.
/// Numeric inference variables may be left unresolved.
pub fn structurally_resolved_type(&self, sp: Span, ty: Ty<'tcx>) -> Ty<'tcx> {
pub fn structurally_resolved_type(&self, sp: Span, mut ty: Ty<'tcx>) -> Ty<'tcx> {
if self.tcx.trait_solver_next() && let ty::Alias(ty::Projection, projection_ty) = *ty.kind() {
let new_infer_ty = self.next_ty_var(TypeVariableOrigin {
kind: TypeVariableOriginKind::NormalizeProjectionType,
span: sp,
});
let obligation = traits::Obligation::new(
self.tcx,
self.misc(sp),
self.param_env,
ty::Binder::dummy(ty::ProjectionPredicate {
projection_ty,
term: new_infer_ty.into(),
}),
);
if self.predicate_may_hold(&obligation) {
self.register_predicate(obligation);
ty = new_infer_ty;
}
}

let ty = self.resolve_vars_with_obligations(ty);
if !ty.is_ty_var() {
ty
Expand Down
12 changes: 6 additions & 6 deletions compiler/rustc_mir_build/src/build/expr/as_rvalue.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -13,7 +13,7 @@ use rustc_middle::mir::AssertKind;
use rustc_middle::mir::Place;
use rustc_middle::mir::*;
use rustc_middle::thir::*;
use rustc_middle::ty::cast::{mir_cast_kind, CastTy};
use rustc_middle::ty::cast::{mir_cast_kind};
use rustc_middle::ty::{self, Ty, UpvarSubsts};
use rustc_span::Span;

Expand Down Expand Up @@ -263,11 +263,11 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
);
(source, ty)
};
let from_ty = CastTy::from_ty(ty);
let cast_ty = CastTy::from_ty(expr.ty);
debug!("ExprKind::Cast from_ty={from_ty:?}, cast_ty={:?}/{cast_ty:?}", expr.ty,);
let cast_kind = mir_cast_kind(ty, expr.ty);
block.and(Rvalue::Cast(cast_kind, source, expr.ty))

let ty = this.structurally_resolved_ty(ty);
let cast_ty = this.structurally_resolved_ty(expr.ty);
let cast_kind = mir_cast_kind(ty, cast_ty);
block.and(Rvalue::Cast(cast_kind, source, cast_ty))
}
ExprKind::Pointer { cast, source } => {
let source = unpack!(
Expand Down
30 changes: 29 additions & 1 deletion compiler/rustc_mir_build/src/build/mod.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -11,6 +11,7 @@ use rustc_hir::def::DefKind;
use rustc_hir::def_id::{DefId, LocalDefId};
use rustc_hir::{GeneratorKind, Node};
use rustc_index::vec::{Idx, IndexVec};
use rustc_infer::infer::type_variable::{TypeVariableOriginKind, TypeVariableOrigin};
use rustc_infer::infer::{InferCtxt, TyCtxtInferExt};
use rustc_middle::hir::place::PlaceBase as HirPlaceBase;
use rustc_middle::middle::region;
Expand All @@ -22,9 +23,11 @@ use rustc_middle::thir::{
};
use rustc_middle::ty::{self, Ty, TyCtxt, TypeVisitableExt};
use rustc_span::symbol::sym;
use rustc_span::Span;
use rustc_span::{Span, DUMMY_SP};
use rustc_span::Symbol;
use rustc_target::spec::abi::Abi;
use rustc_trait_selection::traits;
use rustc_trait_selection::traits::query::evaluate_obligation::InferCtxtExt;

use super::lints;

Expand Down Expand Up @@ -229,6 +232,31 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
fn var_local_id(&self, id: LocalVarId, for_guard: ForGuard) -> Local {
self.var_indices[&id].local_id(for_guard)
}

fn structurally_resolved_ty(&self, ty: Ty<'tcx>) -> Ty<'tcx> {
if self.tcx.trait_solver_next() && let ty::Alias(ty::Projection, projection_ty) = *ty.kind() {
let new_infer_ty = self.infcx.next_ty_var(TypeVariableOrigin {
kind: TypeVariableOriginKind::NormalizeProjectionType,
span: DUMMY_SP,
});
let obligation = traits::Obligation::new(
self.tcx,
traits::ObligationCause::dummy(),
self.param_env,
ty::Binder::dummy(ty::ProjectionPredicate {
projection_ty,
term: new_infer_ty.into(),
}),
);

if self.infcx.predicate_may_hold(&obligation) {
traits::fully_solve_obligation(&self.infcx, obligation);
return self.infcx.resolve_vars_if_possible(new_infer_ty);
}
}

ty
}
}

impl BlockContext {
Expand Down
2 changes: 1 addition & 1 deletion tests/ui/typeck/lazy-norm/cast-checks-handling-projections.rs
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Original file line number Diff line number Diff line change
@@ -1,5 +1,5 @@
// compile-flags: -Ztrait-solver=next
// known-bug: unknown
// check-pass

fn main() {
(0u8 + 0u8) as char;
Expand Down
9 changes: 0 additions & 9 deletions tests/ui/typeck/lazy-norm/cast-checks-handling-projections.stderr
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