From 264cd05b16198c2838ec6cd585bd122491e3f7a9 Mon Sep 17 00:00:00 2001 From: Oli Scherer Date: Mon, 14 Feb 2022 16:10:22 +0000 Subject: Revert "Auto merge of #93893 - oli-obk:sad_revert, r=oli-obk" This reverts commit 6499c5e7fc173a3f55b7a3bd1e6a50e9edef782d, reversing changes made to 78450d2d602b06d9b94349aaf8cece1a4acaf3a8. --- .../src/transform/check_consts/check.rs | 19 +++++++++++++++---- compiler/rustc_const_eval/src/transform/validate.rs | 5 +---- 2 files changed, 16 insertions(+), 8 deletions(-) (limited to 'compiler/rustc_const_eval/src/transform') diff --git a/compiler/rustc_const_eval/src/transform/check_consts/check.rs b/compiler/rustc_const_eval/src/transform/check_consts/check.rs index 223b3ad0cf9..8790baa010c 100644 --- a/compiler/rustc_const_eval/src/transform/check_consts/check.rs +++ b/compiler/rustc_const_eval/src/transform/check_consts/check.rs @@ -11,7 +11,7 @@ use rustc_middle::mir::*; use rustc_middle::ty::cast::CastTy; use rustc_middle::ty::subst::{GenericArgKind, InternalSubsts}; use rustc_middle::ty::{self, adjustment::PointerCast, Instance, InstanceDef, Ty, TyCtxt}; -use rustc_middle::ty::{Binder, TraitPredicate, TraitRef}; +use rustc_middle::ty::{Binder, TraitPredicate, TraitRef, TypeFoldable}; use rustc_mir_dataflow::{self, Analysis}; use rustc_span::{sym, Span, Symbol}; use rustc_trait_selection::traits::error_reporting::InferCtxtExt; @@ -47,7 +47,10 @@ impl<'mir, 'tcx> Qualifs<'mir, 'tcx> { location: Location, ) -> bool { let ty = ccx.body.local_decls[local].ty; - if !NeedsDrop::in_any_value_of_ty(ccx, ty) { + // Peeking into opaque types causes cycles if the current function declares said opaque + // type. Thus we avoid short circuiting on the type and instead run the more expensive + // analysis that looks at the actual usage within this function + if !ty.has_opaque_types() && !NeedsDrop::in_any_value_of_ty(ccx, ty) { return false; } @@ -101,7 +104,10 @@ impl<'mir, 'tcx> Qualifs<'mir, 'tcx> { location: Location, ) -> bool { let ty = ccx.body.local_decls[local].ty; - if !HasMutInterior::in_any_value_of_ty(ccx, ty) { + // Peeking into opaque types causes cycles if the current function declares said opaque + // type. Thus we avoid short circuiting on the type and instead run the more expensive + // analysis that looks at the actual usage within this function + if !ty.has_opaque_types() && !HasMutInterior::in_any_value_of_ty(ccx, ty) { return false; } @@ -148,7 +154,12 @@ impl<'mir, 'tcx> Qualifs<'mir, 'tcx> { // If we know that all values of the return type are structurally matchable, there's no // need to run dataflow. - _ if !CustomEq::in_any_value_of_ty(ccx, ccx.body.return_ty()) => false, + // Opaque types do not participate in const generics or pattern matching, so we can safely count them out. + _ if ccx.body.return_ty().has_opaque_types() + || !CustomEq::in_any_value_of_ty(ccx, ccx.body.return_ty()) => + { + false + } hir::ConstContext::Const | hir::ConstContext::Static(_) => { let mut cursor = FlowSensitiveAnalysis::new(CustomEq, ccx) diff --git a/compiler/rustc_const_eval/src/transform/validate.rs b/compiler/rustc_const_eval/src/transform/validate.rs index deeca78b75d..e68e1a055d9 100644 --- a/compiler/rustc_const_eval/src/transform/validate.rs +++ b/compiler/rustc_const_eval/src/transform/validate.rs @@ -79,7 +79,6 @@ pub fn equal_up_to_regions<'tcx>( } // Normalize lifetimes away on both sides, then compare. - let param_env = param_env.with_reveal_all_normalized(tcx); let normalize = |ty: Ty<'tcx>| { tcx.normalize_erasing_regions( param_env, @@ -171,9 +170,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> { return true; } // Normalize projections and things like that. - // FIXME: We need to reveal_all, as some optimizations change types in ways - // that require unfolding opaque types. - let param_env = self.param_env.with_reveal_all_normalized(self.tcx); + let param_env = self.param_env; let src = self.tcx.normalize_erasing_regions(param_env, src); let dest = self.tcx.normalize_erasing_regions(param_env, dest); -- cgit 1.4.1-3-g733a5 From 4cfaf9a93121f3b4a57f59ebfc1991c6f4b892a8 Mon Sep 17 00:00:00 2001 From: Oli Scherer Date: Thu, 10 Feb 2022 17:53:35 +0000 Subject: Normalize all projections in mir validation again --- .../rustc_const_eval/src/transform/validate.rs | 7 +++++- src/test/ui/impl-trait/projection.rs | 29 ++++++++++++++++++++++ 2 files changed, 35 insertions(+), 1 deletion(-) create mode 100644 src/test/ui/impl-trait/projection.rs (limited to 'compiler/rustc_const_eval/src/transform') diff --git a/compiler/rustc_const_eval/src/transform/validate.rs b/compiler/rustc_const_eval/src/transform/validate.rs index e68e1a055d9..263959f3cb3 100644 --- a/compiler/rustc_const_eval/src/transform/validate.rs +++ b/compiler/rustc_const_eval/src/transform/validate.rs @@ -169,8 +169,13 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> { // Equal types, all is good. return true; } + // Normalization reveals opaque types, but we may be validating MIR while computing + // said opaque types, causing cycles. + if (src, dest).has_opaque_types() { + return true; + } // Normalize projections and things like that. - let param_env = self.param_env; + let param_env = self.param_env.with_reveal_all_normalized(self.tcx); let src = self.tcx.normalize_erasing_regions(param_env, src); let dest = self.tcx.normalize_erasing_regions(param_env, dest); diff --git a/src/test/ui/impl-trait/projection.rs b/src/test/ui/impl-trait/projection.rs new file mode 100644 index 00000000000..21fc6591e97 --- /dev/null +++ b/src/test/ui/impl-trait/projection.rs @@ -0,0 +1,29 @@ +// build-pass +// needs to be build-pass, because it is a regression test for a mir validation failure +// that only happens during codegen. + +struct D; + +trait Tr { + type It; + fn foo(self) -> Option; +} + +impl<'a> Tr for &'a D { + type It = (); + fn foo(self) -> Option<()> { None } +} + +fn run(f: F) + where for<'a> &'a D: Tr, + F: Fn(<&D as Tr>::It), +{ + let d = &D; + while let Some(i) = d.foo() { + f(i); + } +} + +fn main() { + run(|_| {}); +} \ No newline at end of file -- cgit 1.4.1-3-g733a5