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change is_subtype to relate_types

This commit is contained in:
ouz-a 2023-09-30 13:44:31 +03:00
parent cd7f471931
commit 6f0c5ee2d4
15 changed files with 128 additions and 86 deletions

View file

@ -716,14 +716,11 @@ impl<'a, 'b, 'tcx> TypeVerifier<'a, 'b, 'tcx> {
}
PlaceTy::from_ty(fty)
}
ProjectionElem::Subtype(_) => {
let guard = span_mirbug_and_err!(
self,
place,
"ProjectionElem::Subtype shouldn't exist in borrowck"
);
PlaceTy::from_ty(Ty::new_error(tcx, guard))
}
ProjectionElem::Subtype(_) => PlaceTy::from_ty(Ty::new_error_with_message(
tcx,
self.last_span,
"ProjectionElem::Subtype shouldn't exist in borrowck",
)),
ProjectionElem::OpaqueCast(ty) => {
let ty = self.sanitize_type(place, ty);
let ty = self.cx.normalize(ty, location);
@ -2564,7 +2561,6 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
}
}
ProjectionElem::Field(..)
| ProjectionElem::Subtype(..)
| ProjectionElem::Downcast(..)
| ProjectionElem::OpaqueCast(..)
| ProjectionElem::Index(..)
@ -2572,6 +2568,9 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
| ProjectionElem::Subslice { .. } => {
// other field access
}
ProjectionElem::Subtype(_) => {
bug!("ProjectionElem::Subtype shouldn't exist in borrowck")
}
}
}
}

View file

@ -876,7 +876,7 @@ pub(crate) fn codegen_place<'tcx>(
cplace = cplace.place_deref(fx);
}
PlaceElem::OpaqueCast(ty) => bug!("encountered OpaqueCast({ty}) in codegen"),
PlaceElem::Subtype(ty) => cplace = cplace.place_transmute_type(fx, ty),
PlaceElem::Subtype(ty) => cplace = cplace.place_transmute_type(fx, fx.monomorphize(ty)),
PlaceElem::Field(field, _ty) => {
cplace = cplace.place_field(fx, field);
}

View file

@ -674,12 +674,14 @@ impl<'tcx> CPlace<'tcx> {
}
}
/// Used for `ProjectionElem::Subtype`, ty has to be monomorphized before
/// passed on.
pub(crate) fn place_transmute_type(
self,
fx: &mut FunctionCx<'_, '_, 'tcx>,
ty: Ty<'tcx>,
) -> CPlace<'tcx> {
CPlace { inner: self.inner, layout: fx.layout_of(fx.monomorphize(ty)) }
CPlace { inner: self.inner, layout: fx.layout_of(ty) }
}
pub(crate) fn place_field(

View file

@ -13,7 +13,7 @@ use rustc_middle::ty::layout::{
self, FnAbiError, FnAbiOfHelpers, FnAbiRequest, LayoutError, LayoutOf, LayoutOfHelpers,
TyAndLayout,
};
use rustc_middle::ty::{self, GenericArgsRef, ParamEnv, Ty, TyCtxt, TypeFoldable};
use rustc_middle::ty::{self, GenericArgsRef, ParamEnv, Ty, TyCtxt, TypeFoldable, Variance};
use rustc_mir_dataflow::storage::always_storage_live_locals;
use rustc_session::Limit;
use rustc_span::Span;
@ -384,7 +384,7 @@ pub(super) fn mir_assign_valid_types<'tcx>(
// all normal lifetimes are erased, higher-ranked types with their
// late-bound lifetimes are still around and can lead to type
// differences.
if util::is_subtype(tcx, param_env, src.ty, dest.ty) {
if util::relate_types(tcx, param_env, Variance::Covariant, src.ty, dest.ty) {
// Make sure the layout is equal, too -- just to be safe. Miri really
// needs layout equality. For performance reason we skip this check when
// the types are equal. Equal types *can* have different layouts when

View file

@ -7,7 +7,7 @@ use rustc_infer::traits::Reveal;
use rustc_middle::mir::interpret::Scalar;
use rustc_middle::mir::visit::{NonUseContext, PlaceContext, Visitor};
use rustc_middle::mir::*;
use rustc_middle::ty::{self, InstanceDef, ParamEnv, Ty, TyCtxt, TypeVisitableExt};
use rustc_middle::ty::{self, InstanceDef, ParamEnv, Ty, TyCtxt, TypeVisitableExt, Variance};
use rustc_mir_dataflow::impls::MaybeStorageLive;
use rustc_mir_dataflow::storage::always_storage_live_locals;
use rustc_mir_dataflow::{Analysis, ResultsCursor};
@ -16,7 +16,7 @@ use rustc_target::spec::abi::Abi;
use crate::util::is_within_packed;
use crate::util::is_subtype;
use crate::util::relate_types;
#[derive(Copy, Clone, Debug, PartialEq, Eq)]
enum EdgeKind {
@ -604,7 +604,15 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
return true;
}
return crate::util::is_subtype(self.tcx, self.param_env, src, dest);
// After borrowck subtyping should be fully explicit via
// `Subtype` projections.
let variance = if self.mir_phase >= MirPhase::Runtime(RuntimePhase::Initial) {
Variance::Invariant
} else {
Variance::Covariant
};
crate::util::relate_types(self.tcx, self.param_env, variance, src, dest)
}
}
@ -756,9 +764,10 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
}
}
ProjectionElem::Subtype(ty) => {
if !is_subtype(
if !relate_types(
self.tcx,
self.param_env,
Variance::Covariant,
ty,
place_ref.ty(&self.body.local_decls, self.tcx).ty,
) {

View file

@ -5,7 +5,7 @@
use rustc_infer::infer::TyCtxtInferExt;
use rustc_middle::traits::{DefiningAnchor, ObligationCause};
use rustc_middle::ty::{ParamEnv, Ty, TyCtxt};
use rustc_middle::ty::{ParamEnv, Ty, TyCtxt, Variance};
use rustc_trait_selection::traits::ObligationCtxt;
/// Returns whether the two types are equal up to subtyping.
@ -24,16 +24,22 @@ pub fn is_equal_up_to_subtyping<'tcx>(
}
// Check for subtyping in either direction.
is_subtype(tcx, param_env, src, dest) || is_subtype(tcx, param_env, dest, src)
relate_types(tcx, param_env, Variance::Covariant, src, dest)
|| relate_types(tcx, param_env, Variance::Covariant, dest, src)
}
/// Returns whether `src` is a subtype of `dest`, i.e. `src <: dest`.
///
/// For almost all of the use cases variance should be `Covariant`,
/// in `MirPhase` >= `MirPhase::Runtime(RuntimePhase::Initial` variance should
/// be `Invariant`.
///
/// This mostly ignores opaque types as it can be used in constraining contexts
/// while still computing the final underlying type.
pub fn is_subtype<'tcx>(
pub fn relate_types<'tcx>(
tcx: TyCtxt<'tcx>,
param_env: ParamEnv<'tcx>,
variance: Variance,
src: Ty<'tcx>,
dest: Ty<'tcx>,
) -> bool {
@ -48,7 +54,7 @@ pub fn is_subtype<'tcx>(
let cause = ObligationCause::dummy();
let src = ocx.normalize(&cause, param_env, src);
let dest = ocx.normalize(&cause, param_env, dest);
match ocx.sub(&cause, param_env, src, dest) {
match ocx.relate(&cause, param_env, variance, src, dest) {
Ok(()) => {}
Err(_) => return false,
};

View file

@ -7,7 +7,7 @@ mod type_name;
pub use self::alignment::{is_disaligned, is_within_packed};
pub use self::check_validity_requirement::check_validity_requirement;
pub use self::compare_types::{is_equal_up_to_subtyping, is_subtype};
pub use self::compare_types::{is_equal_up_to_subtyping, relate_types};
pub use self::type_name::type_name;
/// Classify whether an operator is "left-homogeneous", i.e., the LHS has the

View file

@ -218,7 +218,13 @@ impl<'tcx> Inliner<'tcx> {
// Normally, this shouldn't be required, but trait normalization failure can create a
// validation ICE.
let output_type = callee_body.return_ty();
if !util::is_subtype(self.tcx, self.param_env, output_type, destination_ty) {
if !util::relate_types(
self.tcx,
self.param_env,
ty::Variance::Covariant,
output_type,
destination_ty,
) {
trace!(?output_type, ?destination_ty);
return Err("failed to normalize return type");
}
@ -248,7 +254,13 @@ impl<'tcx> Inliner<'tcx> {
self_arg_ty.into_iter().chain(arg_tuple_tys).zip(callee_body.args_iter())
{
let input_type = callee_body.local_decls[input].ty;
if !util::is_subtype(self.tcx, self.param_env, input_type, arg_ty) {
if !util::relate_types(
self.tcx,
self.param_env,
ty::Variance::Covariant,
input_type,
arg_ty,
) {
trace!(?arg_ty, ?input_type);
return Err("failed to normalize tuple argument type");
}
@ -257,7 +269,13 @@ impl<'tcx> Inliner<'tcx> {
for (arg, input) in args.iter().zip(callee_body.args_iter()) {
let input_type = callee_body.local_decls[input].ty;
let arg_ty = arg.ty(&caller_body.local_decls, self.tcx);
if !util::is_subtype(self.tcx, self.param_env, input_type, arg_ty) {
if !util::relate_types(
self.tcx,
self.param_env,
ty::Variance::Covariant,
input_type,
arg_ty,
) {
trace!(?arg_ty, ?input_type);
return Err("failed to normalize argument type");
}

View file

@ -23,6 +23,7 @@ use rustc_middle::traits::query::NoSolution;
use rustc_middle::ty::error::TypeError;
use rustc_middle::ty::ToPredicate;
use rustc_middle::ty::TypeFoldable;
use rustc_middle::ty::Variance;
use rustc_middle::ty::{self, Ty, TyCtxt};
use rustc_session::config::TraitSolver;
@ -156,6 +157,20 @@ impl<'a, 'tcx> ObligationCtxt<'a, 'tcx> {
.map(|infer_ok| self.register_infer_ok_obligations(infer_ok))
}
pub fn relate<T: ToTrace<'tcx>>(
&self,
cause: &ObligationCause<'tcx>,
param_env: ty::ParamEnv<'tcx>,
variance: Variance,
expected: T,
actual: T,
) -> Result<(), TypeError<'tcx>> {
self.infcx
.at(cause, param_env)
.relate(DefineOpaqueTypes::Yes, expected, variance, actual)
.map(|infer_ok| self.register_infer_ok_obligations(infer_ok))
}
/// Checks whether `expected` is a supertype of `actual`: `expected :> actual`.
pub fn sup<T: ToTrace<'tcx>>(
&self,

@ -0,0 +1 @@
Subproject commit 9434648ba82a0519222677bcc3fdf8b4f1ac5ced

View file

@ -1,14 +0,0 @@
// run-pass
#![deny(drop_bounds)]
// As a special exemption, `impl Drop` in the return position raises no error.
// This allows a convenient way to return an unnamed drop guard.
fn voldemort_type() -> impl Drop {
struct Voldemort;
impl Drop for Voldemort {
fn drop(&mut self) {}
}
Voldemort
}
fn main() {
let _ = voldemort_type();
}

View file

@ -7,12 +7,12 @@
let mut _2: std::pin::Pin<&mut {generator@$DIR/inline_generator.rs:16:5: 16:8}>;
let mut _3: &mut {generator@$DIR/inline_generator.rs:16:5: 16:8};
let mut _4: {generator@$DIR/inline_generator.rs:16:5: 16:8};
+ let mut _5: bool;
+ let mut _6: bool;
scope 1 {
debug _r => _1;
}
+ scope 2 (inlined g) {
+ let mut _5: [generator@$DIR/inline_generator.rs:16:5: 16:8];
+ let mut _5: {generator@$DIR/inline_generator.rs:16:5: 16:8};
+ }
+ scope 3 (inlined Pin::<&mut {generator@$DIR/inline_generator.rs:16:5: 16:8}>::new) {
+ debug pointer => _3;
@ -23,10 +23,10 @@
+ }
+ }
+ scope 6 (inlined g::{closure#0}) {
+ debug a => _5;
+ let mut _6: &mut {generator@$DIR/inline_generator.rs:16:5: 16:8};
+ let mut _7: u32;
+ let mut _8: i32;
+ debug a => _6;
+ let mut _7: &mut {generator@$DIR/inline_generator.rs:16:5: 16:8};
+ let mut _8: u32;
+ let mut _9: i32;
+ }
bb0: {
@ -35,21 +35,24 @@
StorageLive(_3);
StorageLive(_4);
- _4 = g() -> [return: bb1, unwind unreachable];
+ _4 = {generator@$DIR/inline_generator.rs:16:5: 16:8 (#0)};
+ StorageLive(_5);
+ _5 = {generator@$DIR/inline_generator.rs:16:5: 16:8 (#0)};
+ _4 = move (_5as {generator@$DIR/inline_generator.rs:16:5: 16:8});
+ StorageDead(_5);
+ _3 = &mut _4;
+ _2 = Pin::<&mut {generator@$DIR/inline_generator.rs:16:5: 16:8}> { pointer: move _3 };
+ StorageDead(_3);
+ StorageLive(_5);
+ _5 = const false;
+ _6 = (_2.0: &mut {generator@$DIR/inline_generator.rs:16:5: 16:8});
+ _7 = discriminant((*_6));
+ switchInt(move _7) -> [0: bb3, 1: bb7, 3: bb8, otherwise: bb9];
+ StorageLive(_6);
+ _6 = const false;
+ _7 = (_2.0: &mut {generator@$DIR/inline_generator.rs:16:5: 16:8});
+ _8 = discriminant((*_7));
+ switchInt(move _8) -> [0: bb3, 1: bb7, 3: bb8, otherwise: bb9];
}
bb1: {
- _3 = &mut _4;
- _2 = Pin::<&mut {generator@$DIR/inline_generator.rs:16:5: 16:8}>::new(move _3) -> [return: bb2, unwind unreachable];
+ StorageDead(_5);
+ StorageDead(_6);
+ StorageDead(_2);
+ drop(_4) -> [return: bb2, unwind unreachable];
}
@ -66,8 +69,8 @@
bb3: {
- StorageDead(_2);
- drop(_4) -> [return: bb4, unwind unreachable];
+ StorageLive(_8);
+ switchInt(_5) -> [0: bb4, otherwise: bb5];
+ StorageLive(_9);
+ switchInt(_6) -> [0: bb4, otherwise: bb5];
}
bb4: {
@ -75,18 +78,18 @@
- _0 = const ();
- StorageDead(_1);
- return;
+ _8 = const 13_i32;
+ _9 = const 13_i32;
+ goto -> bb6;
+ }
+
+ bb5: {
+ _8 = const 7_i32;
+ _9 = const 7_i32;
+ goto -> bb6;
+ }
+
+ bb6: {
+ _1 = GeneratorState::<i32, bool>::Yielded(move _8);
+ discriminant((*_6)) = 3;
+ _1 = GeneratorState::<i32, bool>::Yielded(move _9);
+ discriminant((*_7)) = 3;
+ goto -> bb1;
+ }
+
@ -95,10 +98,10 @@
+ }
+
+ bb8: {
+ StorageLive(_8);
+ StorageDead(_8);
+ _1 = GeneratorState::<i32, bool>::Complete(_5);
+ discriminant((*_6)) = 1;
+ StorageLive(_9);
+ StorageDead(_9);
+ _1 = GeneratorState::<i32, bool>::Complete(_6);
+ discriminant((*_7)) = 1;
+ goto -> bb1;
+ }
+

View file

@ -7,12 +7,12 @@
let mut _2: std::pin::Pin<&mut {generator@$DIR/inline_generator.rs:16:5: 16:8}>;
let mut _3: &mut {generator@$DIR/inline_generator.rs:16:5: 16:8};
let mut _4: {generator@$DIR/inline_generator.rs:16:5: 16:8};
+ let mut _5: bool;
+ let mut _6: bool;
scope 1 {
debug _r => _1;
}
+ scope 2 (inlined g) {
+ let mut _5: [generator@$DIR/inline_generator.rs:16:5: 16:8];
+ let mut _5: {generator@$DIR/inline_generator.rs:16:5: 16:8};
+ }
+ scope 3 (inlined Pin::<&mut {generator@$DIR/inline_generator.rs:16:5: 16:8}>::new) {
+ debug pointer => _3;
@ -23,10 +23,10 @@
+ }
+ }
+ scope 6 (inlined g::{closure#0}) {
+ debug a => _5;
+ let mut _6: &mut {generator@$DIR/inline_generator.rs:16:5: 16:8};
+ let mut _7: u32;
+ let mut _8: i32;
+ debug a => _6;
+ let mut _7: &mut {generator@$DIR/inline_generator.rs:16:5: 16:8};
+ let mut _8: u32;
+ let mut _9: i32;
+ }
bb0: {
@ -38,7 +38,10 @@
- }
-
- bb1: {
+ _4 = {generator@$DIR/inline_generator.rs:16:5: 16:8 (#0)};
+ StorageLive(_5);
+ _5 = {generator@$DIR/inline_generator.rs:16:5: 16:8 (#0)};
+ _4 = move (_5as {generator@$DIR/inline_generator.rs:16:5: 16:8});
+ StorageDead(_5);
_3 = &mut _4;
- _2 = Pin::<&mut {generator@$DIR/inline_generator.rs:16:5: 16:8}>::new(move _3) -> [return: bb2, unwind: bb5];
- }
@ -47,11 +50,11 @@
+ _2 = Pin::<&mut {generator@$DIR/inline_generator.rs:16:5: 16:8}> { pointer: move _3 };
StorageDead(_3);
- _1 = <{generator@$DIR/inline_generator.rs:16:5: 16:8} as Generator<bool>>::resume(move _2, const false) -> [return: bb3, unwind: bb5];
+ StorageLive(_5);
+ _5 = const false;
+ _6 = (_2.0: &mut {generator@$DIR/inline_generator.rs:16:5: 16:8});
+ _7 = discriminant((*_6));
+ switchInt(move _7) -> [0: bb5, 1: bb9, 3: bb10, otherwise: bb11];
+ StorageLive(_6);
+ _6 = const false;
+ _7 = (_2.0: &mut {generator@$DIR/inline_generator.rs:16:5: 16:8});
+ _8 = discriminant((*_7));
+ switchInt(move _8) -> [0: bb5, 1: bb9, 3: bb10, otherwise: bb11];
}
- bb3: {
@ -82,23 +85,23 @@
+ }
+
+ bb5: {
+ StorageLive(_8);
+ switchInt(_5) -> [0: bb6, otherwise: bb7];
+ StorageLive(_9);
+ switchInt(_6) -> [0: bb6, otherwise: bb7];
+ }
+
+ bb6: {
+ _8 = const 13_i32;
+ _9 = const 13_i32;
+ goto -> bb8;
+ }
+
+ bb7: {
+ _8 = const 7_i32;
+ _9 = const 7_i32;
+ goto -> bb8;
+ }
+
+ bb8: {
+ _1 = GeneratorState::<i32, bool>::Yielded(move _8);
+ discriminant((*_6)) = 3;
+ _1 = GeneratorState::<i32, bool>::Yielded(move _9);
+ discriminant((*_7)) = 3;
+ goto -> bb1;
+ }
+
@ -107,10 +110,10 @@
+ }
+
+ bb10: {
+ StorageLive(_8);
+ StorageDead(_8);
+ _1 = GeneratorState::<i32, bool>::Complete(_5);
+ discriminant((*_6)) = 1;
+ StorageLive(_9);
+ StorageDead(_9);
+ _1 = GeneratorState::<i32, bool>::Complete(_6);
+ discriminant((*_7)) = 1;
+ goto -> bb1;
+ }
+

View file

@ -107,7 +107,7 @@ fn main() -> () {
_14 = {closure@main::{closure#0}};
Retag(_14);
_29 = move _14 as for<'a> fn(&'a i32) -> &'a i32 (PointerCoercion(ClosureFnPointer(Normal)));
_13 = move (_29 Subtyped as for<'a> fn(&'a i32) -> &'a i32);
_13 = move (_29as for<'a> fn(&'a i32) -> &'a i32);
StorageDead(_14);
StorageLive(_15);
StorageLive(_16);

View file

@ -107,7 +107,7 @@ fn main() -> () {
_14 = {closure@main::{closure#0}};
Retag(_14);
_29 = move _14 as for<'a> fn(&'a i32) -> &'a i32 (PointerCoercion(ClosureFnPointer(Normal)));
_13 = move (_29 Subtyped as for<'a> fn(&'a i32) -> &'a i32);
_13 = move (_29as for<'a> fn(&'a i32) -> &'a i32);
StorageDead(_14);
StorageLive(_15);
StorageLive(_16);