From 9835e2ae736235810b4ea1c162ca5e65c547e770 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sat, 18 May 2024 04:49:50 +0200 Subject: Merging upstream version 1.71.1+dfsg1. Signed-off-by: Daniel Baumann --- .../rustc_mir_transform/src/deduce_param_attrs.rs | 39 +++++++++++----------- 1 file changed, 20 insertions(+), 19 deletions(-) (limited to 'compiler/rustc_mir_transform/src/deduce_param_attrs.rs') diff --git a/compiler/rustc_mir_transform/src/deduce_param_attrs.rs b/compiler/rustc_mir_transform/src/deduce_param_attrs.rs index e5c3fa564..a133c9d47 100644 --- a/compiler/rustc_mir_transform/src/deduce_param_attrs.rs +++ b/compiler/rustc_mir_transform/src/deduce_param_attrs.rs @@ -8,8 +8,8 @@ use rustc_hir::def_id::LocalDefId; use rustc_index::bit_set::BitSet; use rustc_middle::mir::visit::{NonMutatingUseContext, PlaceContext, Visitor}; -use rustc_middle::mir::{Body, Local, Location, Operand, Terminator, TerminatorKind, RETURN_PLACE}; -use rustc_middle::ty::{self, DeducedParamAttrs, ParamEnv, Ty, TyCtxt}; +use rustc_middle::mir::{Body, Location, Operand, Place, Terminator, TerminatorKind, RETURN_PLACE}; +use rustc_middle::ty::{self, DeducedParamAttrs, Ty, TyCtxt}; use rustc_session::config::OptLevel; /// A visitor that determines which arguments have been mutated. We can't use the mutability field @@ -29,31 +29,31 @@ impl DeduceReadOnly { } impl<'tcx> Visitor<'tcx> for DeduceReadOnly { - fn visit_local(&mut self, local: Local, mut context: PlaceContext, _: Location) { + fn visit_place(&mut self, place: &Place<'tcx>, context: PlaceContext, _location: Location) { // We're only interested in arguments. - if local == RETURN_PLACE || local.index() > self.mutable_args.domain_size() { + if place.local == RETURN_PLACE || place.local.index() > self.mutable_args.domain_size() { return; } - // Replace place contexts that are moves with copies. This is safe in all cases except - // function argument position, which we already handled in `visit_terminator()` by using the - // ArgumentChecker. See the comment in that method for more details. - // - // In the future, we might want to move this out into a separate pass, but for now let's - // just do it on the fly because that's faster. - if matches!(context, PlaceContext::NonMutatingUse(NonMutatingUseContext::Move)) { - context = PlaceContext::NonMutatingUse(NonMutatingUseContext::Copy); - } - - match context { - PlaceContext::MutatingUse(..) - | PlaceContext::NonMutatingUse(NonMutatingUseContext::Move) => { + let mark_as_mutable = match context { + PlaceContext::MutatingUse(..) => { // This is a mutation, so mark it as such. - self.mutable_args.insert(local.index() - 1); + true + } + PlaceContext::NonMutatingUse(NonMutatingUseContext::AddressOf) => { + // Whether mutating though a `&raw const` is allowed is still undecided, so we + // disable any sketchy `readonly` optimizations for now. + // But we only need to do this if the pointer would point into the argument. + !place.is_indirect() } PlaceContext::NonMutatingUse(..) | PlaceContext::NonUse(..) => { // Not mutating, so it's fine. + false } + }; + + if mark_as_mutable { + self.mutable_args.insert(place.local.index() - 1); } } @@ -198,11 +198,12 @@ pub fn deduced_param_attrs<'tcx>( // see [1]. // // [1]: https://github.com/rust-lang/rust/pull/103172#discussion_r999139997 + let param_env = tcx.param_env_reveal_all_normalized(def_id); let mut deduced_param_attrs = tcx.arena.alloc_from_iter( body.local_decls.iter().skip(1).take(body.arg_count).enumerate().map( |(arg_index, local_decl)| DeducedParamAttrs { read_only: !deduce_read_only.mutable_args.contains(arg_index) - && local_decl.ty.is_freeze(tcx, ParamEnv::reveal_all()), + && local_decl.ty.is_freeze(tcx, param_env), }, ), ); -- cgit v1.2.3