diff options
29 files changed, 363 insertions, 149 deletions
diff --git a/compiler/rustc_interface/src/tests.rs b/compiler/rustc_interface/src/tests.rs index d405d044cae..5c8c51c8bbc 100644 --- a/compiler/rustc_interface/src/tests.rs +++ b/compiler/rustc_interface/src/tests.rs @@ -818,8 +818,8 @@ fn test_unstable_options_tracking_hash() { tracked!(min_function_alignment, Some(Align::EIGHT)); tracked!(mir_emit_retag, true); tracked!(mir_enable_passes, vec![("DestProp".to_string(), false)]); - tracked!(mir_keep_place_mention, true); tracked!(mir_opt_level, Some(4)); + tracked!(mir_preserve_ub, true); tracked!(move_size_limit, Some(4096)); tracked!(mutable_noalias, false); tracked!(next_solver, NextSolverConfig { coherence: true, globally: true }); diff --git a/compiler/rustc_mir_transform/src/early_otherwise_branch.rs b/compiler/rustc_mir_transform/src/early_otherwise_branch.rs index d49f5d9f9c3..c7feb9e949b 100644 --- a/compiler/rustc_mir_transform/src/early_otherwise_branch.rs +++ b/compiler/rustc_mir_transform/src/early_otherwise_branch.rs @@ -223,7 +223,7 @@ impl<'tcx> crate::MirPass<'tcx> for EarlyOtherwiseBranch { // Since this optimization adds new basic blocks and invalidates others, // clean up the cfg to make it nicer for other passes if should_cleanup { - simplify_cfg(body); + simplify_cfg(tcx, body); } } diff --git a/compiler/rustc_mir_transform/src/inline.rs b/compiler/rustc_mir_transform/src/inline.rs index 69e80ed54ea..c5732194424 100644 --- a/compiler/rustc_mir_transform/src/inline.rs +++ b/compiler/rustc_mir_transform/src/inline.rs @@ -63,7 +63,7 @@ impl<'tcx> crate::MirPass<'tcx> for Inline { let _guard = span.enter(); if inline::<NormalInliner<'tcx>>(tcx, body) { debug!("running simplify cfg on {:?}", body.source); - simplify_cfg(body); + simplify_cfg(tcx, body); deref_finder(tcx, body); } } @@ -99,7 +99,7 @@ impl<'tcx> crate::MirPass<'tcx> for ForceInline { let _guard = span.enter(); if inline::<ForceInliner<'tcx>>(tcx, body) { debug!("running simplify cfg on {:?}", body.source); - simplify_cfg(body); + simplify_cfg(tcx, body); deref_finder(tcx, body); } } diff --git a/compiler/rustc_mir_transform/src/jump_threading.rs b/compiler/rustc_mir_transform/src/jump_threading.rs index 8b4b214a3d4..9732225e48d 100644 --- a/compiler/rustc_mir_transform/src/jump_threading.rs +++ b/compiler/rustc_mir_transform/src/jump_threading.rs @@ -90,11 +90,7 @@ impl<'tcx> crate::MirPass<'tcx> for JumpThreading { }; for bb in body.basic_blocks.indices() { - let old_len = finder.opportunities.len(); - // If we have any const-eval errors discard any opportunities found - if finder.start_from_switch(bb).is_none() { - finder.opportunities.truncate(old_len); - } + finder.start_from_switch(bb); } let opportunities = finder.opportunities; @@ -201,28 +197,26 @@ impl<'a, 'tcx> TOFinder<'a, 'tcx> { /// Recursion entry point to find threading opportunities. #[instrument(level = "trace", skip(self))] - fn start_from_switch(&mut self, bb: BasicBlock) -> Option<()> { + fn start_from_switch(&mut self, bb: BasicBlock) { let bbdata = &self.body[bb]; if bbdata.is_cleanup || self.loop_headers.contains(bb) { - return Some(()); + return; } - let Some((discr, targets)) = bbdata.terminator().kind.as_switch() else { return Some(()) }; - let Some(discr) = discr.place() else { return Some(()) }; + let Some((discr, targets)) = bbdata.terminator().kind.as_switch() else { return }; + let Some(discr) = discr.place() else { return }; debug!(?discr, ?bb); let discr_ty = discr.ty(self.body, self.tcx).ty; - let Ok(discr_layout) = self.ecx.layout_of(discr_ty) else { - return Some(()); - }; + let Ok(discr_layout) = self.ecx.layout_of(discr_ty) else { return }; - let Some(discr) = self.map.find(discr.as_ref()) else { return Some(()) }; + let Some(discr) = self.map.find(discr.as_ref()) else { return }; debug!(?discr); let cost = CostChecker::new(self.tcx, self.typing_env, None, self.body); let mut state = State::new_reachable(); let conds = if let Some((value, then, else_)) = targets.as_static_if() { - let value = ScalarInt::try_from_uint(value, discr_layout.size)?; + let Some(value) = ScalarInt::try_from_uint(value, discr_layout.size) else { return }; self.arena.alloc_from_iter([ Condition { value, polarity: Polarity::Eq, target: then }, Condition { value, polarity: Polarity::Ne, target: else_ }, @@ -248,10 +242,10 @@ impl<'a, 'tcx> TOFinder<'a, 'tcx> { mut state: State<ConditionSet<'a>>, mut cost: CostChecker<'_, 'tcx>, depth: usize, - ) -> Option<()> { + ) { // Do not thread through loop headers. if self.loop_headers.contains(bb) { - return Some(()); + return; } debug!(cost = ?cost.cost()); @@ -259,16 +253,16 @@ impl<'a, 'tcx> TOFinder<'a, 'tcx> { self.body.basic_blocks[bb].statements.iter().enumerate().rev() { if self.is_empty(&state) { - return Some(()); + return; } cost.visit_statement(stmt, Location { block: bb, statement_index }); if cost.cost() > MAX_COST { - return Some(()); + return; } // Attempt to turn the `current_condition` on `lhs` into a condition on another place. - self.process_statement(bb, stmt, &mut state)?; + self.process_statement(bb, stmt, &mut state); // When a statement mutates a place, assignments to that place that happen // above the mutation cannot fulfill a condition. @@ -280,7 +274,7 @@ impl<'a, 'tcx> TOFinder<'a, 'tcx> { } if self.is_empty(&state) || depth >= MAX_BACKTRACK { - return Some(()); + return; } let last_non_rec = self.opportunities.len(); @@ -293,9 +287,9 @@ impl<'a, 'tcx> TOFinder<'a, 'tcx> { match term.kind { TerminatorKind::SwitchInt { ref discr, ref targets } => { self.process_switch_int(discr, targets, bb, &mut state); - self.find_opportunity(pred, state, cost, depth + 1)?; + self.find_opportunity(pred, state, cost, depth + 1); } - _ => self.recurse_through_terminator(pred, || state, &cost, depth)?, + _ => self.recurse_through_terminator(pred, || state, &cost, depth), } } else if let &[ref predecessors @ .., last_pred] = &predecessors[..] { for &pred in predecessors { @@ -320,13 +314,12 @@ impl<'a, 'tcx> TOFinder<'a, 'tcx> { let first = &mut new_tos[0]; *first = ThreadingOpportunity { chain: vec![bb], target: first.target }; self.opportunities.truncate(last_non_rec + 1); - return Some(()); + return; } for op in self.opportunities[last_non_rec..].iter_mut() { op.chain.push(bb); } - Some(()) } /// Extract the mutated place from a statement. @@ -440,23 +433,23 @@ impl<'a, 'tcx> TOFinder<'a, 'tcx> { lhs: PlaceIndex, rhs: &Operand<'tcx>, state: &mut State<ConditionSet<'a>>, - ) -> Option<()> { + ) { match rhs { // If we expect `lhs ?= A`, we have an opportunity if we assume `constant == A`. Operand::Constant(constant) => { - let constant = self - .ecx - .eval_mir_constant(&constant.const_, constant.span, None) - .discard_err()?; + let Some(constant) = + self.ecx.eval_mir_constant(&constant.const_, constant.span, None).discard_err() + else { + return; + }; self.process_constant(bb, lhs, constant, state); } // Transfer the conditions on the copied rhs. Operand::Move(rhs) | Operand::Copy(rhs) => { - let Some(rhs) = self.map.find(rhs.as_ref()) else { return Some(()) }; + let Some(rhs) = self.map.find(rhs.as_ref()) else { return }; state.insert_place_idx(rhs, lhs, &self.map); } } - Some(()) } #[instrument(level = "trace", skip(self))] @@ -466,18 +459,14 @@ impl<'a, 'tcx> TOFinder<'a, 'tcx> { lhs_place: &Place<'tcx>, rhs: &Rvalue<'tcx>, state: &mut State<ConditionSet<'a>>, - ) -> Option<()> { - let Some(lhs) = self.map.find(lhs_place.as_ref()) else { - return Some(()); - }; + ) { + let Some(lhs) = self.map.find(lhs_place.as_ref()) else { return }; match rhs { - Rvalue::Use(operand) => self.process_operand(bb, lhs, operand, state)?, + Rvalue::Use(operand) => self.process_operand(bb, lhs, operand, state), // Transfer the conditions on the copy rhs. - Rvalue::CopyForDeref(rhs) => { - self.process_operand(bb, lhs, &Operand::Copy(*rhs), state)? - } + Rvalue::CopyForDeref(rhs) => self.process_operand(bb, lhs, &Operand::Copy(*rhs), state), Rvalue::Discriminant(rhs) => { - let Some(rhs) = self.map.find_discr(rhs.as_ref()) else { return Some(()) }; + let Some(rhs) = self.map.find_discr(rhs.as_ref()) else { return }; state.insert_place_idx(rhs, lhs, &self.map); } // If we expect `lhs ?= A`, we have an opportunity if we assume `constant == A`. @@ -485,7 +474,7 @@ impl<'a, 'tcx> TOFinder<'a, 'tcx> { let agg_ty = lhs_place.ty(self.body, self.tcx).ty; let lhs = match kind { // Do not support unions. - AggregateKind::Adt(.., Some(_)) => return Some(()), + AggregateKind::Adt(.., Some(_)) => return, AggregateKind::Adt(_, variant_index, ..) if agg_ty.is_enum() => { if let Some(discr_target) = self.map.apply(lhs, TrackElem::Discriminant) && let Some(discr_value) = self @@ -498,23 +487,23 @@ impl<'a, 'tcx> TOFinder<'a, 'tcx> { if let Some(idx) = self.map.apply(lhs, TrackElem::Variant(*variant_index)) { idx } else { - return Some(()); + return; } } _ => lhs, }; for (field_index, operand) in operands.iter_enumerated() { if let Some(field) = self.map.apply(lhs, TrackElem::Field(field_index)) { - self.process_operand(bb, field, operand, state)?; + self.process_operand(bb, field, operand, state); } } } // Transfer the conditions on the copy rhs, after inverting the value of the condition. Rvalue::UnaryOp(UnOp::Not, Operand::Move(place) | Operand::Copy(place)) => { let layout = self.ecx.layout_of(place.ty(self.body, self.tcx).ty).unwrap(); - let Some(conditions) = state.try_get_idx(lhs, &self.map) else { return Some(()) }; - let Some(place) = self.map.find(place.as_ref()) else { return Some(()) }; - let conds = conditions.map(self.arena, |mut cond| { + let Some(conditions) = state.try_get_idx(lhs, &self.map) else { return }; + let Some(place) = self.map.find(place.as_ref()) else { return }; + let Some(conds) = conditions.map(self.arena, |mut cond| { cond.value = self .ecx .unary_op(UnOp::Not, &ImmTy::from_scalar_int(cond.value, layout)) @@ -522,7 +511,9 @@ impl<'a, 'tcx> TOFinder<'a, 'tcx> { .to_scalar_int() .discard_err()?; Some(cond) - })?; + }) else { + return; + }; state.insert_value_idx(place, conds, &self.map); } // We expect `lhs ?= A`. We found `lhs = Eq(rhs, B)`. @@ -532,34 +523,38 @@ impl<'a, 'tcx> TOFinder<'a, 'tcx> { box (Operand::Move(place) | Operand::Copy(place), Operand::Constant(value)) | box (Operand::Constant(value), Operand::Move(place) | Operand::Copy(place)), ) => { - let Some(conditions) = state.try_get_idx(lhs, &self.map) else { return Some(()) }; - let Some(place) = self.map.find(place.as_ref()) else { return Some(()) }; + let Some(conditions) = state.try_get_idx(lhs, &self.map) else { return }; + let Some(place) = self.map.find(place.as_ref()) else { return }; let equals = match op { BinOp::Eq => ScalarInt::TRUE, BinOp::Ne => ScalarInt::FALSE, - _ => return Some(()), + _ => return, }; if value.const_.ty().is_floating_point() { // Floating point equality does not follow bit-patterns. // -0.0 and NaN both have special rules for equality, // and therefore we cannot use integer comparisons for them. // Avoid handling them, though this could be extended in the future. - return Some(()); + return; } - let value = value.const_.try_eval_scalar_int(self.tcx, self.typing_env)?; - let conds = conditions.map(self.arena, |c| { + let Some(value) = value.const_.try_eval_scalar_int(self.tcx, self.typing_env) + else { + return; + }; + let Some(conds) = conditions.map(self.arena, |c| { Some(Condition { value, polarity: if c.matches(equals) { Polarity::Eq } else { Polarity::Ne }, ..c }) - })?; + }) else { + return; + }; state.insert_value_idx(place, conds, &self.map); } _ => {} } - Some(()) } #[instrument(level = "trace", skip(self))] @@ -568,7 +563,7 @@ impl<'a, 'tcx> TOFinder<'a, 'tcx> { bb: BasicBlock, stmt: &Statement<'tcx>, state: &mut State<ConditionSet<'a>>, - ) -> Option<()> { + ) { let register_opportunity = |c: Condition| { debug!(?bb, ?c.target, "register"); self.opportunities.push(ThreadingOpportunity { chain: vec![bb], target: c.target }) @@ -581,32 +576,30 @@ impl<'a, 'tcx> TOFinder<'a, 'tcx> { // If we expect `discriminant(place) ?= A`, // we have an opportunity if `variant_index ?= A`. StatementKind::SetDiscriminant { box place, variant_index } => { - let Some(discr_target) = self.map.find_discr(place.as_ref()) else { - return Some(()); - }; + let Some(discr_target) = self.map.find_discr(place.as_ref()) else { return }; let enum_ty = place.ty(self.body, self.tcx).ty; // `SetDiscriminant` guarantees that the discriminant is now `variant_index`. // Even if the discriminant write does nothing due to niches, it is UB to set the // discriminant when the data does not encode the desired discriminant. - let discr = - self.ecx.discriminant_for_variant(enum_ty, *variant_index).discard_err()?; - self.process_immediate(bb, discr_target, discr, state); + let Some(discr) = + self.ecx.discriminant_for_variant(enum_ty, *variant_index).discard_err() + else { + return; + }; + self.process_immediate(bb, discr_target, discr, state) } // If we expect `lhs ?= true`, we have an opportunity if we assume `lhs == true`. StatementKind::Intrinsic(box NonDivergingIntrinsic::Assume( Operand::Copy(place) | Operand::Move(place), )) => { - let Some(conditions) = state.try_get(place.as_ref(), &self.map) else { - return Some(()); - }; - conditions.iter_matches(ScalarInt::TRUE).for_each(register_opportunity); + let Some(conditions) = state.try_get(place.as_ref(), &self.map) else { return }; + conditions.iter_matches(ScalarInt::TRUE).for_each(register_opportunity) } StatementKind::Assign(box (lhs_place, rhs)) => { - self.process_assign(bb, lhs_place, rhs, state)?; + self.process_assign(bb, lhs_place, rhs, state) } _ => {} } - Some(()) } #[instrument(level = "trace", skip(self, state, cost))] @@ -617,7 +610,7 @@ impl<'a, 'tcx> TOFinder<'a, 'tcx> { state: impl FnOnce() -> State<ConditionSet<'a>>, cost: &CostChecker<'_, 'tcx>, depth: usize, - ) -> Option<()> { + ) { let term = self.body.basic_blocks[bb].terminator(); let place_to_flood = match term.kind { // We come from a target, so those are not possible. @@ -632,9 +625,9 @@ impl<'a, 'tcx> TOFinder<'a, 'tcx> { | TerminatorKind::FalseUnwind { .. } | TerminatorKind::Yield { .. } => bug!("{term:?} invalid"), // Cannot reason about inline asm. - TerminatorKind::InlineAsm { .. } => return Some(()), + TerminatorKind::InlineAsm { .. } => return, // `SwitchInt` is handled specially. - TerminatorKind::SwitchInt { .. } => return Some(()), + TerminatorKind::SwitchInt { .. } => return, // We can recurse, no thing particular to do. TerminatorKind::Goto { .. } => None, // Flood the overwritten place, and progress through. diff --git a/compiler/rustc_mir_transform/src/match_branches.rs b/compiler/rustc_mir_transform/src/match_branches.rs index 5059837328e..b37241185c9 100644 --- a/compiler/rustc_mir_transform/src/match_branches.rs +++ b/compiler/rustc_mir_transform/src/match_branches.rs @@ -43,7 +43,7 @@ impl<'tcx> crate::MirPass<'tcx> for MatchBranchSimplification { } if should_cleanup { - simplify_cfg(body); + simplify_cfg(tcx, body); } } diff --git a/compiler/rustc_mir_transform/src/remove_place_mention.rs b/compiler/rustc_mir_transform/src/remove_place_mention.rs index 15fe77d5319..cb598ceb4df 100644 --- a/compiler/rustc_mir_transform/src/remove_place_mention.rs +++ b/compiler/rustc_mir_transform/src/remove_place_mention.rs @@ -8,7 +8,7 @@ pub(super) struct RemovePlaceMention; impl<'tcx> crate::MirPass<'tcx> for RemovePlaceMention { fn is_enabled(&self, sess: &rustc_session::Session) -> bool { - !sess.opts.unstable_opts.mir_keep_place_mention + !sess.opts.unstable_opts.mir_preserve_ub } fn run_pass(&self, _: TyCtxt<'tcx>, body: &mut Body<'tcx>) { diff --git a/compiler/rustc_mir_transform/src/remove_unneeded_drops.rs b/compiler/rustc_mir_transform/src/remove_unneeded_drops.rs index 8a8cdafc690..43f80508e4a 100644 --- a/compiler/rustc_mir_transform/src/remove_unneeded_drops.rs +++ b/compiler/rustc_mir_transform/src/remove_unneeded_drops.rs @@ -35,7 +35,7 @@ impl<'tcx> crate::MirPass<'tcx> for RemoveUnneededDrops { // if we applied optimizations, we potentially have some cfg to cleanup to // make it easier for further passes if should_simplify { - simplify_cfg(body); + simplify_cfg(tcx, body); } } diff --git a/compiler/rustc_mir_transform/src/simplify.rs b/compiler/rustc_mir_transform/src/simplify.rs index 5947637cded..4f2cce8ac10 100644 --- a/compiler/rustc_mir_transform/src/simplify.rs +++ b/compiler/rustc_mir_transform/src/simplify.rs @@ -26,6 +26,13 @@ //! Here the block (`{ return; }`) has the return type `char`, rather than `()`, but the MIR we //! naively generate still contains the `_a = ()` write in the unreachable block "after" the //! return. +//! +//! **WARNING**: This is one of the few optimizations that runs on built and analysis MIR, and +//! so its effects may affect the type-checking, borrow-checking, and other analysis of MIR. +//! We must be extremely careful to only apply optimizations that preserve UB and all +//! non-determinism, since changes here can affect which programs compile in an insta-stable way. +//! The normal logic that a program with UB can be changed to do anything does not apply to +//! pre-"runtime" MIR! use rustc_index::{Idx, IndexSlice, IndexVec}; use rustc_middle::mir::visit::{MutVisitor, MutatingUseContext, PlaceContext, Visitor}; @@ -66,8 +73,8 @@ impl SimplifyCfg { } } -pub(super) fn simplify_cfg(body: &mut Body<'_>) { - CfgSimplifier::new(body).simplify(); +pub(super) fn simplify_cfg<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) { + CfgSimplifier::new(tcx, body).simplify(); remove_dead_blocks(body); // FIXME: Should probably be moved into some kind of pass manager @@ -79,9 +86,9 @@ impl<'tcx> crate::MirPass<'tcx> for SimplifyCfg { self.name() } - fn run_pass(&self, _: TyCtxt<'tcx>, body: &mut Body<'tcx>) { + fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) { debug!("SimplifyCfg({:?}) - simplifying {:?}", self.name(), body.source); - simplify_cfg(body); + simplify_cfg(tcx, body); } fn is_required(&self) -> bool { @@ -90,12 +97,13 @@ impl<'tcx> crate::MirPass<'tcx> for SimplifyCfg { } struct CfgSimplifier<'a, 'tcx> { + preserve_switch_reads: bool, basic_blocks: &'a mut IndexSlice<BasicBlock, BasicBlockData<'tcx>>, pred_count: IndexVec<BasicBlock, u32>, } impl<'a, 'tcx> CfgSimplifier<'a, 'tcx> { - fn new(body: &'a mut Body<'tcx>) -> Self { + fn new(tcx: TyCtxt<'tcx>, body: &'a mut Body<'tcx>) -> Self { let mut pred_count = IndexVec::from_elem(0u32, &body.basic_blocks); // we can't use mir.predecessors() here because that counts @@ -110,9 +118,12 @@ impl<'a, 'tcx> CfgSimplifier<'a, 'tcx> { } } + // Preserve `SwitchInt` reads on built and analysis MIR, or if `-Zmir-preserve-ub`. + let preserve_switch_reads = matches!(body.phase, MirPhase::Built | MirPhase::Analysis(_)) + || tcx.sess.opts.unstable_opts.mir_preserve_ub; let basic_blocks = body.basic_blocks_mut(); - CfgSimplifier { basic_blocks, pred_count } + CfgSimplifier { preserve_switch_reads, basic_blocks, pred_count } } fn simplify(mut self) { @@ -253,9 +264,15 @@ impl<'a, 'tcx> CfgSimplifier<'a, 'tcx> { // turn a branch with all successors identical to a goto fn simplify_branch(&mut self, terminator: &mut Terminator<'tcx>) -> bool { - match terminator.kind { - TerminatorKind::SwitchInt { .. } => {} - _ => return false, + // Removing a `SwitchInt` terminator may remove reads that result in UB, + // so we must not apply this optimization before borrowck or when + // `-Zmir-preserve-ub` is set. + if self.preserve_switch_reads { + return false; + } + + let TerminatorKind::SwitchInt { .. } = terminator.kind else { + return false; }; let first_succ = { diff --git a/compiler/rustc_session/src/options.rs b/compiler/rustc_session/src/options.rs index 1b0794f79d3..36eee5f3086 100644 --- a/compiler/rustc_session/src/options.rs +++ b/compiler/rustc_session/src/options.rs @@ -2322,12 +2322,12 @@ options! { mir_include_spans: MirIncludeSpans = (MirIncludeSpans::default(), parse_mir_include_spans, [UNTRACKED], "include extra comments in mir pretty printing, like line numbers and statement indices, \ details about types, etc. (boolean for all passes, 'nll' to enable in NLL MIR only, default: 'nll')"), - mir_keep_place_mention: bool = (false, parse_bool, [TRACKED], - "keep place mention MIR statements, interpreted e.g., by miri; implies -Zmir-opt-level=0 \ - (default: no)"), #[rustc_lint_opt_deny_field_access("use `Session::mir_opt_level` instead of this field")] mir_opt_level: Option<usize> = (None, parse_opt_number, [TRACKED], "MIR optimization level (0-4; default: 1 in non optimized builds and 2 in optimized builds)"), + mir_preserve_ub: bool = (false, parse_bool, [TRACKED], + "keep place mention statements and reads in trivial SwitchInt terminators, which are interpreted \ + e.g., by miri; implies -Zmir-opt-level=0 (default: no)"), mir_strip_debuginfo: MirStripDebugInfo = (MirStripDebugInfo::None, parse_mir_strip_debuginfo, [TRACKED], "Whether to remove some of the MIR debug info from methods. Default: None"), move_size_limit: Option<usize> = (None, parse_opt_number, [TRACKED], diff --git a/library/core/src/iter/adapters/enumerate.rs b/library/core/src/iter/adapters/enumerate.rs index bd093e279c3..f7b9f0b7a5e 100644 --- a/library/core/src/iter/adapters/enumerate.rs +++ b/library/core/src/iter/adapters/enumerate.rs @@ -23,6 +23,39 @@ impl<I> Enumerate<I> { pub(in crate::iter) fn new(iter: I) -> Enumerate<I> { Enumerate { iter, count: 0 } } + + /// Retrieve the current position of the iterator. + /// + /// If the iterator has not advanced, the position returned will be 0. + /// + /// The position may also exceed the bounds of the iterator to allow for calculating + /// the displacement of the iterator from following calls to [`Iterator::next`]. + /// + /// # Examples + /// + /// ``` + /// #![feature(next_index)] + /// + /// let arr = ['a', 'b']; + /// + /// let mut iter = arr.iter().enumerate(); + /// + /// assert_eq!(iter.next_index(), 0); + /// assert_eq!(iter.next(), Some((0, &'a'))); + /// + /// assert_eq!(iter.next_index(), 1); + /// assert_eq!(iter.next_index(), 1); + /// assert_eq!(iter.next(), Some((1, &'b'))); + /// + /// assert_eq!(iter.next_index(), 2); + /// assert_eq!(iter.next(), None); + /// assert_eq!(iter.next_index(), 2); + /// ``` + #[inline] + #[unstable(feature = "next_index", issue = "130711")] + pub fn next_index(&self) -> usize { + self.count + } } #[stable(feature = "rust1", since = "1.0.0")] diff --git a/library/coretests/tests/iter/adapters/enumerate.rs b/library/coretests/tests/iter/adapters/enumerate.rs index b57d51c077e..2294f856b58 100644 --- a/library/coretests/tests/iter/adapters/enumerate.rs +++ b/library/coretests/tests/iter/adapters/enumerate.rs @@ -120,3 +120,13 @@ fn test_double_ended_enumerate() { assert_eq!(it.next_back(), Some((2, 3))); assert_eq!(it.next(), None); } + +#[test] +fn test_empty_iterator_enumerate_next_index() { + let mut it = empty::<i32>().enumerate(); + assert_eq!(it.next_index(), 0); + assert_eq!(it.next_index(), 0); + assert_eq!(it.next(), None); + assert_eq!(it.next_index(), 0); + assert_eq!(it.next_index(), 0); +} diff --git a/library/coretests/tests/lib.rs b/library/coretests/tests/lib.rs index 1c43bfe0ed4..ac111575938 100644 --- a/library/coretests/tests/lib.rs +++ b/library/coretests/tests/lib.rs @@ -63,6 +63,7 @@ #![feature(maybe_uninit_write_slice)] #![feature(min_specialization)] #![feature(never_type)] +#![feature(next_index)] #![feature(numfmt)] #![feature(pattern)] #![feature(pointer_is_aligned_to)] diff --git a/src/bootstrap/src/core/build_steps/compile.rs b/src/bootstrap/src/core/build_steps/compile.rs index 6a5b38dd504..68fa42ee9e6 100644 --- a/src/bootstrap/src/core/build_steps/compile.rs +++ b/src/bootstrap/src/core/build_steps/compile.rs @@ -1194,8 +1194,7 @@ pub fn rustc_cargo( let enzyme_dir = builder.build.out.join(arch).join("enzyme").join("lib"); cargo.rustflag("-L").rustflag(enzyme_dir.to_str().expect("Invalid path")); - if !builder.config.dry_run() { - let llvm_config = builder.llvm_config(builder.config.build).unwrap(); + if let Some(llvm_config) = builder.llvm_config(builder.config.build) { let llvm_version_major = llvm::get_llvm_version_major(builder, &llvm_config); cargo.rustflag("-l").rustflag(&format!("Enzyme-{llvm_version_major}")); } diff --git a/src/bootstrap/src/core/build_steps/setup.rs b/src/bootstrap/src/core/build_steps/setup.rs index 80d92135dd3..83083e12ef1 100644 --- a/src/bootstrap/src/core/build_steps/setup.rs +++ b/src/bootstrap/src/core/build_steps/setup.rs @@ -584,6 +584,7 @@ Select which editor you would like to set up [default: None]: "; "51068d4747a13732440d1a8b8f432603badb1864fa431d83d0fd4f8fa57039e0", "d29af4d949bbe2371eac928a3c31cf9496b1701aa1c45f11cd6c759865ad5c45", "b5dd299b93dca3ceeb9b335f929293cb3d4bf4977866fbe7ceeac2a8a9f99088", + "631c837b0e98ae35fd48b0e5f743b1ca60adadf2d0a2b23566ba25df372cf1a9", ], EditorKind::Helix => &[ "2d3069b8cf1b977e5d4023965eb6199597755e6c96c185ed5f2854f98b83d233", @@ -602,10 +603,12 @@ Select which editor you would like to set up [default: None]: "; "4eecb58a2168b252077369da446c30ed0e658301efe69691979d1ef0443928f4", "c394386e6133bbf29ffd32c8af0bb3d4aac354cba9ee051f29612aa9350f8f8d", "e53e9129ca5ee5dcbd6ec8b68c2d87376474eb154992deba3c6d9ab1703e0717", + "f954316090936c7e590c253ca9d524008375882fa13c5b41d7e2547a896ff893", ], EditorKind::Zed => &[ "bbce727c269d1bd0c98afef4d612eb4ce27aea3c3a8968c5f10b31affbc40b6c", "a5380cf5dd9328731aecc5dfb240d16dac46ed272126b9728006151ef42f5909", + "2e96bf0d443852b12f016c8fc9840ab3d0a2b4fe0b0fb3a157e8d74d5e7e0e26", ], } } diff --git a/src/etc/rust_analyzer_eglot.el b/src/etc/rust_analyzer_eglot.el index 6b40371d9af..90bd38aa894 100644 --- a/src/etc/rust_analyzer_eglot.el +++ b/src/etc/rust_analyzer_eglot.el @@ -8,10 +8,11 @@ "check" "--json-output"]) :linkedProjects ["Cargo.toml" - "src/bootstrap/Cargo.toml" - "src/tools/rust-analyzer/Cargo.toml" "compiler/rustc_codegen_cranelift/Cargo.toml" - "compiler/rustc_codegen_gcc/Cargo.toml"] + "compiler/rustc_codegen_gcc/Cargo.toml" + "library/Cargo.toml" + "src/bootstrap/Cargo.toml" + "src/tools/rust-analyzer/Cargo.toml"] :rustfmt ( :overrideCommand ["build/host/rustfmt/bin/rustfmt" "--edition=2021"]) :procMacro ( :server "build/host/stage0/libexec/rust-analyzer-proc-macro-srv" diff --git a/src/etc/rust_analyzer_settings.json b/src/etc/rust_analyzer_settings.json index da7d326a512..5ce886a9b65 100644 --- a/src/etc/rust_analyzer_settings.json +++ b/src/etc/rust_analyzer_settings.json @@ -9,11 +9,11 @@ ], "rust-analyzer.linkedProjects": [ "Cargo.toml", + "compiler/rustc_codegen_cranelift/Cargo.toml", + "compiler/rustc_codegen_gcc/Cargo.toml", "library/Cargo.toml", "src/bootstrap/Cargo.toml", - "src/tools/rust-analyzer/Cargo.toml", - "compiler/rustc_codegen_cranelift/Cargo.toml", - "compiler/rustc_codegen_gcc/Cargo.toml" + "src/tools/rust-analyzer/Cargo.toml" ], "rust-analyzer.rustfmt.overrideCommand": [ "${workspaceFolder}/build/host/rustfmt/bin/rustfmt", @@ -36,5 +36,10 @@ }, "rust-analyzer.server.extraEnv": { "RUSTUP_TOOLCHAIN": "nightly" + }, + "files.associations": { + "*.fixed": "rust", + "*.pp": "rust", + "*.mir": "rust" } } diff --git a/src/etc/rust_analyzer_zed.json b/src/etc/rust_analyzer_zed.json index abc6ddbc213..3461ff887d9 100644 --- a/src/etc/rust_analyzer_zed.json +++ b/src/etc/rust_analyzer_zed.json @@ -21,15 +21,15 @@ }, "linkedProjects": [ "Cargo.toml", + "compiler/rustc_codegen_cranelift/Cargo.toml", + "compiler/rustc_codegen_gcc/Cargo.toml", "library/Cargo.toml", "src/bootstrap/Cargo.toml", - "src/tools/rust-analyzer/Cargo.toml", - "compiler/rustc_codegen_cranelift/Cargo.toml", - "compiler/rustc_codegen_gcc/Cargo.toml" + "src/tools/rust-analyzer/Cargo.toml" ], "procMacro": { - "enable": true, - "server": "${workspaceFolder}/build/host/stage0/libexec/rust-analyzer-proc-macro-srv" + "enable": true, + "server": "${workspaceFolder}/build/host/stage0/libexec/rust-analyzer-proc-macro-srv" }, "rustc": { "source": "./Cargo.toml" @@ -47,5 +47,8 @@ } } } + }, + "file_types": { + "Rust": ["fixed", "pp", "mir"] } } diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs index 034ecb2f6c1..6ecb67c776c 100644 --- a/src/librustdoc/clean/mod.rs +++ b/src/librustdoc/clean/mod.rs @@ -2773,10 +2773,35 @@ fn clean_maybe_renamed_item<'tcx>( ) -> Vec<Item> { use hir::ItemKind; - let def_id = item.owner_id.to_def_id(); - let mut name = if renamed.is_some() { renamed } else { cx.tcx.hir_opt_name(item.hir_id()) }; + fn get_name( + cx: &DocContext<'_>, + item: &hir::Item<'_>, + renamed: Option<Symbol>, + ) -> Option<Symbol> { + renamed.or_else(|| cx.tcx.hir_opt_name(item.hir_id())) + } + let def_id = item.owner_id.to_def_id(); cx.with_param_env(def_id, |cx| { + // These kinds of item either don't need a `name` or accept a `None` one so we handle them + // before. + match item.kind { + ItemKind::Impl(impl_) => return clean_impl(impl_, item.owner_id.def_id, cx), + ItemKind::Use(path, kind) => { + return clean_use_statement( + item, + get_name(cx, item, renamed), + path, + kind, + cx, + &mut FxHashSet::default(), + ); + } + _ => {} + } + + let mut name = get_name(cx, item, renamed).unwrap(); + let kind = match item.kind { ItemKind::Static(_, ty, mutability, body_id) => StaticItem(Static { type_: Box::new(clean_ty(ty, cx)), @@ -2815,7 +2840,7 @@ fn clean_maybe_renamed_item<'tcx>( item_type: Some(type_), })), item.owner_id.def_id.to_def_id(), - name.unwrap(), + name, import_id, renamed, )); @@ -2838,17 +2863,14 @@ fn clean_maybe_renamed_item<'tcx>( generics: clean_generics(generics, cx), fields: variant_data.fields().iter().map(|x| clean_field(x, cx)).collect(), }), - ItemKind::Impl(impl_) => return clean_impl(impl_, item.owner_id.def_id, cx), ItemKind::Macro(_, macro_def, MacroKind::Bang) => MacroItem(Macro { - source: display_macro_source(cx, name.unwrap(), macro_def), + source: display_macro_source(cx, name, macro_def), macro_rules: macro_def.macro_rules, }), - ItemKind::Macro(_, _, macro_kind) => { - clean_proc_macro(item, name.as_mut().unwrap(), macro_kind, cx) - } + ItemKind::Macro(_, _, macro_kind) => clean_proc_macro(item, &mut name, macro_kind, cx), // proc macros can have a name set by attributes ItemKind::Fn { ref sig, generics, body: body_id, .. } => { - clean_fn_or_proc_macro(item, sig, generics, body_id, name.as_mut().unwrap(), cx) + clean_fn_or_proc_macro(item, sig, generics, body_id, &mut name, cx) } ItemKind::Trait(_, _, _, generics, bounds, item_ids) => { let items = item_ids @@ -2864,10 +2886,7 @@ fn clean_maybe_renamed_item<'tcx>( })) } ItemKind::ExternCrate(orig_name, _) => { - return clean_extern_crate(item, name.unwrap(), orig_name, cx); - } - ItemKind::Use(path, kind) => { - return clean_use_statement(item, name, path, kind, cx, &mut FxHashSet::default()); + return clean_extern_crate(item, name, orig_name, cx); } _ => span_bug!(item.span, "not yet converted"), }; @@ -2876,7 +2895,7 @@ fn clean_maybe_renamed_item<'tcx>( cx, kind, item.owner_id.def_id.to_def_id(), - name.unwrap(), + name, import_id, renamed, )] diff --git a/src/tools/miri/src/lib.rs b/src/tools/miri/src/lib.rs index 5921ba86639..b6b2684dc6d 100644 --- a/src/tools/miri/src/lib.rs +++ b/src/tools/miri/src/lib.rs @@ -169,7 +169,7 @@ pub const MIRI_DEFAULT_ARGS: &[&str] = &[ "-Zalways-encode-mir", "-Zextra-const-ub-checks", "-Zmir-emit-retag", - "-Zmir-keep-place-mention", + "-Zmir-preserve-ub", "-Zmir-opt-level=0", "-Zmir-enable-passes=-CheckAlignment,-CheckNull", // Deduplicating diagnostics means we miss events when tracking what happens during an diff --git a/src/tools/miri/tests/fail/read_from_trivial_switch.rs b/src/tools/miri/tests/fail/read_from_trivial_switch.rs new file mode 100644 index 00000000000..d34b1cd5820 --- /dev/null +++ b/src/tools/miri/tests/fail/read_from_trivial_switch.rs @@ -0,0 +1,14 @@ +// Ensure that we don't optimize out `SwitchInt` reads even if that terminator +// branches to the same basic block on every target, since the operand may have +// side-effects that affect analysis of the MIR. +// +// See <https://github.com/rust-lang/miri/issues/4237>. + +use std::mem::MaybeUninit; + +fn main() { + let uninit: MaybeUninit<i32> = MaybeUninit::uninit(); + let bad_ref: &i32 = unsafe { uninit.assume_init_ref() }; + let &(0 | _) = bad_ref; + //~^ ERROR: Undefined Behavior: using uninitialized data, but this operation requires initialized memory +} diff --git a/src/tools/miri/tests/fail/read_from_trivial_switch.stderr b/src/tools/miri/tests/fail/read_from_trivial_switch.stderr new file mode 100644 index 00000000000..6b3d4539b96 --- /dev/null +++ b/src/tools/miri/tests/fail/read_from_trivial_switch.stderr @@ -0,0 +1,15 @@ +error: Undefined Behavior: using uninitialized data, but this operation requires initialized memory + --> tests/fail/read_from_trivial_switch.rs:LL:CC + | +LL | let &(0 | _) = bad_ref; + | ^^^^^^^^ using uninitialized data, but this operation requires initialized memory + | + = help: this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior + = help: see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information + = note: BACKTRACE: + = note: inside `main` at tests/fail/read_from_trivial_switch.rs:LL:CC + +note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace + +error: aborting due to 1 previous error + diff --git a/tests/mir-opt/building/match/exponential_or.match_tuple.SimplifyCfg-initial.after.mir b/tests/mir-opt/building/match/exponential_or.match_tuple.SimplifyCfg-initial.after.mir index d52241b459e..2a965fe67b9 100644 --- a/tests/mir-opt/building/match/exponential_or.match_tuple.SimplifyCfg-initial.after.mir +++ b/tests/mir-opt/building/match/exponential_or.match_tuple.SimplifyCfg-initial.after.mir @@ -24,43 +24,47 @@ fn match_tuple(_1: (u32, bool, Option<i32>, u32)) -> u32 { bb1: { _0 = const 0_u32; - goto -> bb10; + goto -> bb11; } bb2: { - _2 = discriminant((_1.2: std::option::Option<i32>)); - switchInt(move _2) -> [0: bb4, 1: bb3, otherwise: bb1]; + switchInt(copy (_1.1: bool)) -> [0: bb3, otherwise: bb3]; } bb3: { - switchInt(copy (((_1.2: std::option::Option<i32>) as Some).0: i32)) -> [1: bb4, 8: bb4, otherwise: bb1]; + _2 = discriminant((_1.2: std::option::Option<i32>)); + switchInt(move _2) -> [0: bb5, 1: bb4, otherwise: bb1]; } bb4: { - _5 = Le(const 6_u32, copy (_1.3: u32)); - switchInt(move _5) -> [0: bb5, otherwise: bb7]; + switchInt(copy (((_1.2: std::option::Option<i32>) as Some).0: i32)) -> [1: bb5, 8: bb5, otherwise: bb1]; } bb5: { - _3 = Le(const 13_u32, copy (_1.3: u32)); - switchInt(move _3) -> [0: bb1, otherwise: bb6]; + _5 = Le(const 6_u32, copy (_1.3: u32)); + switchInt(move _5) -> [0: bb6, otherwise: bb8]; } bb6: { - _4 = Le(copy (_1.3: u32), const 16_u32); - switchInt(move _4) -> [0: bb1, otherwise: bb8]; + _3 = Le(const 13_u32, copy (_1.3: u32)); + switchInt(move _3) -> [0: bb1, otherwise: bb7]; } bb7: { - _6 = Le(copy (_1.3: u32), const 9_u32); - switchInt(move _6) -> [0: bb5, otherwise: bb8]; + _4 = Le(copy (_1.3: u32), const 16_u32); + switchInt(move _4) -> [0: bb1, otherwise: bb9]; } bb8: { - falseEdge -> [real: bb9, imaginary: bb1]; + _6 = Le(copy (_1.3: u32), const 9_u32); + switchInt(move _6) -> [0: bb6, otherwise: bb9]; } bb9: { + falseEdge -> [real: bb10, imaginary: bb1]; + } + + bb10: { StorageLive(_7); _7 = copy (_1.0: u32); StorageLive(_8); @@ -74,10 +78,10 @@ fn match_tuple(_1: (u32, bool, Option<i32>, u32)) -> u32 { StorageDead(_9); StorageDead(_8); StorageDead(_7); - goto -> bb10; + goto -> bb11; } - bb10: { + bb11: { return; } } diff --git a/tests/mir-opt/dead-store-elimination/place_mention.rs b/tests/mir-opt/dead-store-elimination/place_mention.rs index 5e4a286a208..1848a028297 100644 --- a/tests/mir-opt/dead-store-elimination/place_mention.rs +++ b/tests/mir-opt/dead-store-elimination/place_mention.rs @@ -2,7 +2,7 @@ // and don't remove it as a dead store. // //@ test-mir-pass: DeadStoreElimination-initial -//@ compile-flags: -Zmir-keep-place-mention +//@ compile-flags: -Zmir-preserve-ub // EMIT_MIR place_mention.main.DeadStoreElimination-initial.diff fn main() { diff --git a/tests/mir-opt/or_pattern.single_switchint.SimplifyCfg-initial.after.mir b/tests/mir-opt/or_pattern.single_switchint.SimplifyCfg-initial.after.mir index 889ff6f9f5e..be0931eaa61 100644 --- a/tests/mir-opt/or_pattern.single_switchint.SimplifyCfg-initial.after.mir +++ b/tests/mir-opt/or_pattern.single_switchint.SimplifyCfg-initial.after.mir @@ -14,7 +14,7 @@ fn single_switchint() -> () { } bb1: { - switchInt(copy (_2.0: i32)) -> [3: bb8, 4: bb8, otherwise: bb7]; + switchInt(copy (_2.0: i32)) -> [3: bb9, 4: bb9, otherwise: bb8]; } bb2: { @@ -22,7 +22,7 @@ fn single_switchint() -> () { } bb3: { - falseEdge -> [real: bb12, imaginary: bb4]; + falseEdge -> [real: bb14, imaginary: bb4]; } bb4: { @@ -30,43 +30,51 @@ fn single_switchint() -> () { } bb5: { - falseEdge -> [real: bb11, imaginary: bb6]; + falseEdge -> [real: bb13, imaginary: bb6]; } bb6: { - falseEdge -> [real: bb10, imaginary: bb1]; + switchInt(copy (_2.1: bool)) -> [0: bb7, otherwise: bb7]; } bb7: { - _1 = const 5_i32; - goto -> bb13; + falseEdge -> [real: bb12, imaginary: bb1]; } bb8: { - falseEdge -> [real: bb9, imaginary: bb7]; + _1 = const 5_i32; + goto -> bb15; } bb9: { - _1 = const 4_i32; - goto -> bb13; + switchInt(copy (_2.1: bool)) -> [0: bb10, otherwise: bb10]; } bb10: { - _1 = const 3_i32; - goto -> bb13; + falseEdge -> [real: bb11, imaginary: bb8]; } bb11: { - _1 = const 2_i32; - goto -> bb13; + _1 = const 4_i32; + goto -> bb15; } bb12: { - _1 = const 1_i32; - goto -> bb13; + _1 = const 3_i32; + goto -> bb15; } bb13: { + _1 = const 2_i32; + goto -> bb15; + } + + bb14: { + _1 = const 1_i32; + goto -> bb15; + } + + bb15: { StorageDead(_2); StorageDead(_1); _0 = const (); diff --git a/tests/mir-opt/read_from_trivial_switch.main.SimplifyCfg-initial.diff b/tests/mir-opt/read_from_trivial_switch.main.SimplifyCfg-initial.diff new file mode 100644 index 00000000000..87758408a1c --- /dev/null +++ b/tests/mir-opt/read_from_trivial_switch.main.SimplifyCfg-initial.diff @@ -0,0 +1,49 @@ +- // MIR for `main` before SimplifyCfg-initial ++ // MIR for `main` after SimplifyCfg-initial + + fn main() -> () { + let mut _0: (); + let _1: &i32; + let _2: i32; + scope 1 { + debug ref_ => _1; + scope 2 { + } + } + + bb0: { + StorageLive(_1); + StorageLive(_2); + _2 = const 1_i32; + _1 = &_2; + FakeRead(ForLet(None), _1); + PlaceMention(_1); +- switchInt(copy (*_1)) -> [0: bb2, otherwise: bb1]; ++ switchInt(copy (*_1)) -> [0: bb1, otherwise: bb1]; + } + + bb1: { +- goto -> bb5; +- } +- +- bb2: { +- goto -> bb5; +- } +- +- bb3: { +- goto -> bb1; +- } +- +- bb4: { +- FakeRead(ForMatchedPlace(None), _1); +- unreachable; +- } +- +- bb5: { + _0 = const (); + StorageDead(_2); + StorageDead(_1); + return; + } + } + diff --git a/tests/mir-opt/read_from_trivial_switch.rs b/tests/mir-opt/read_from_trivial_switch.rs new file mode 100644 index 00000000000..1c64c1d45e8 --- /dev/null +++ b/tests/mir-opt/read_from_trivial_switch.rs @@ -0,0 +1,15 @@ +// Ensure that we don't optimize out `SwitchInt` reads even if that terminator +// branches to the same basic block on every target, since the operand may have +// side-effects that affect analysis of the MIR. +// +// See <https://github.com/rust-lang/miri/issues/4237>. + +//@ test-mir-pass: SimplifyCfg-initial +//@ compile-flags: -Zmir-preserve-ub + +// EMIT_MIR read_from_trivial_switch.main.SimplifyCfg-initial.diff +fn main() { + let ref_ = &1i32; + // CHECK: switchInt + let &(0 | _) = ref_; +} diff --git a/tests/ui/pattern/uninit-trivial.rs b/tests/ui/pattern/uninit-trivial.rs new file mode 100644 index 00000000000..6ea6796c1c1 --- /dev/null +++ b/tests/ui/pattern/uninit-trivial.rs @@ -0,0 +1,8 @@ +// Regression test for the semantic changes in +// <https://github.com/rust-lang/rust/pull/139042>. + +fn main() { + let x; + let (0 | _) = x; + //~^ ERROR used binding `x` isn't initialized +} diff --git a/tests/ui/pattern/uninit-trivial.stderr b/tests/ui/pattern/uninit-trivial.stderr new file mode 100644 index 00000000000..2ff8557c945 --- /dev/null +++ b/tests/ui/pattern/uninit-trivial.stderr @@ -0,0 +1,16 @@ +error[E0381]: used binding `x` isn't initialized + --> $DIR/uninit-trivial.rs:6:10 + | +LL | let x; + | - binding declared here but left uninitialized +LL | let (0 | _) = x; + | ^^^^^ `x` used here but it isn't initialized + | +help: consider assigning a value + | +LL | let x = 42; + | ++++ + +error: aborting due to 1 previous error + +For more information about this error, try `rustc --explain E0381`. diff --git a/triagebot.toml b/triagebot.toml index 226f024c156..0f17d022fbb 100644 --- a/triagebot.toml +++ b/triagebot.toml @@ -659,6 +659,7 @@ message_on_add = [ """\ /poll Approve stable backport of #{number}? approve +approve (but does not justify new dot release on its own) decline don't know """, |