diff options
Diffstat (limited to '')
-rw-r--r-- | compiler/rustc_const_eval/src/transform/validate.rs | 76 |
1 files changed, 13 insertions, 63 deletions
diff --git a/compiler/rustc_const_eval/src/transform/validate.rs b/compiler/rustc_const_eval/src/transform/validate.rs index 81b82a21f..5c9263dc5 100644 --- a/compiler/rustc_const_eval/src/transform/validate.rs +++ b/compiler/rustc_const_eval/src/transform/validate.rs @@ -2,7 +2,7 @@ use rustc_data_structures::fx::FxHashSet; use rustc_index::bit_set::BitSet; -use rustc_infer::infer::TyCtxtInferExt; +use rustc_infer::traits::Reveal; use rustc_middle::mir::interpret::Scalar; use rustc_middle::mir::visit::NonUseContext::VarDebugInfo; use rustc_middle::mir::visit::{PlaceContext, Visitor}; @@ -12,8 +12,7 @@ use rustc_middle::mir::{ ProjectionElem, RuntimePhase, Rvalue, SourceScope, Statement, StatementKind, Terminator, TerminatorKind, UnOp, START_BLOCK, }; -use rustc_middle::ty::fold::BottomUpFolder; -use rustc_middle::ty::{self, InstanceDef, ParamEnv, Ty, TyCtxt, TypeFoldable, TypeVisitable}; +use rustc_middle::ty::{self, InstanceDef, ParamEnv, Ty, TyCtxt, TypeVisitable}; use rustc_mir_dataflow::impls::MaybeStorageLive; use rustc_mir_dataflow::storage::always_storage_live_locals; use rustc_mir_dataflow::{Analysis, ResultsCursor}; @@ -46,8 +45,11 @@ impl<'tcx> MirPass<'tcx> for Validator { return; } let def_id = body.source.def_id(); - let param_env = tcx.param_env(def_id); let mir_phase = self.mir_phase; + let param_env = match mir_phase.reveal() { + Reveal::UserFacing => tcx.param_env(def_id), + Reveal::All => tcx.param_env_reveal_all_normalized(def_id), + }; let always_live_locals = always_storage_live_locals(body); let storage_liveness = MaybeStorageLive::new(always_live_locals) @@ -70,44 +72,6 @@ impl<'tcx> MirPass<'tcx> for Validator { } } -/// Returns whether the two types are equal up to lifetimes. -/// All lifetimes, including higher-ranked ones, get ignored for this comparison. -/// (This is unlike the `erasing_regions` methods, which keep higher-ranked lifetimes for soundness reasons.) -/// -/// The point of this function is to approximate "equal up to subtyping". However, -/// the approximation is incorrect as variance is ignored. -pub fn equal_up_to_regions<'tcx>( - tcx: TyCtxt<'tcx>, - param_env: ParamEnv<'tcx>, - src: Ty<'tcx>, - dest: Ty<'tcx>, -) -> bool { - // Fast path. - if src == dest { - return true; - } - - // Normalize lifetimes away on both sides, then compare. - let normalize = |ty: Ty<'tcx>| { - tcx.try_normalize_erasing_regions(param_env, ty).unwrap_or(ty).fold_with( - &mut BottomUpFolder { - tcx, - // FIXME: We erase all late-bound lifetimes, but this is not fully correct. - // If you have a type like `<for<'a> fn(&'a u32) as SomeTrait>::Assoc`, - // this is not necessarily equivalent to `<fn(&'static u32) as SomeTrait>::Assoc`, - // since one may have an `impl SomeTrait for fn(&32)` and - // `impl SomeTrait for fn(&'static u32)` at the same time which - // specify distinct values for Assoc. (See also #56105) - lt_op: |_| tcx.lifetimes.re_erased, - // Leave consts and types unchanged. - ct_op: |ct| ct, - ty_op: |ty| ty, - }, - ) - }; - tcx.infer_ctxt().build().can_eq(param_env, normalize(src), normalize(dest)).is_ok() -} - struct TypeChecker<'a, 'tcx> { when: &'a str, body: &'a Body<'tcx>, @@ -121,6 +85,7 @@ struct TypeChecker<'a, 'tcx> { } impl<'a, 'tcx> TypeChecker<'a, 'tcx> { + #[track_caller] fn fail(&self, location: Location, msg: impl AsRef<str>) { let span = self.body.source_info(location).span; // We use `delay_span_bug` as we might see broken MIR when other errors have already @@ -183,22 +148,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> { return true; } - // Normalize projections and things like that. - // Type-changing assignments can happen when subtyping is used. While - // all normal lifetimes are erased, higher-ranked types with their - // late-bound lifetimes are still around and can lead to type - // differences. So we compare ignoring lifetimes. - - // First, try with reveal_all. This might not work in some cases, as the predicates - // can be cleared in reveal_all mode. We try the reveal first anyways as it is used - // by some other passes like inlining as well. - let param_env = self.param_env.with_reveal_all_normalized(self.tcx); - if equal_up_to_regions(self.tcx, param_env, src, dest) { - return true; - } - - // If this fails, we can try it without the reveal. - equal_up_to_regions(self.tcx, self.param_env, src, dest) + crate::util::is_subtype(self.tcx, self.param_env, src, dest) } } @@ -281,12 +231,12 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> { let check_equal = |this: &Self, location, f_ty| { if !this.mir_assign_valid_types(ty, f_ty) { this.fail( - location, - format!( - "Field projection `{:?}.{:?}` specified type `{:?}`, but actual type is `{:?}`", - parent, f, ty, f_ty + location, + format!( + "Field projection `{:?}.{:?}` specified type `{:?}`, but actual type is `{:?}`", + parent, f, ty, f_ty + ) ) - ) } }; |