diff options
Diffstat (limited to 'compiler/rustc_mir_transform/src')
17 files changed, 145 insertions, 134 deletions
diff --git a/compiler/rustc_mir_transform/src/check_unsafety.rs b/compiler/rustc_mir_transform/src/check_unsafety.rs index 9c22b5df73c..adf6ae4c727 100644 --- a/compiler/rustc_mir_transform/src/check_unsafety.rs +++ b/compiler/rustc_mir_transform/src/check_unsafety.rs @@ -490,10 +490,10 @@ fn check_unused_unsafe( unused_unsafes } -fn unsafety_check_result<'tcx>( - tcx: TyCtxt<'tcx>, +fn unsafety_check_result( + tcx: TyCtxt<'_>, def: ty::WithOptConstParam<LocalDefId>, -) -> &'tcx UnsafetyCheckResult { +) -> &UnsafetyCheckResult { debug!("unsafety_violations({:?})", def); // N.B., this borrow is valid because all the consumers of diff --git a/compiler/rustc_mir_transform/src/cleanup_post_borrowck.rs b/compiler/rustc_mir_transform/src/cleanup_post_borrowck.rs index 3378923c22c..d435d3ee69b 100644 --- a/compiler/rustc_mir_transform/src/cleanup_post_borrowck.rs +++ b/compiler/rustc_mir_transform/src/cleanup_post_borrowck.rs @@ -1,39 +1,44 @@ -//! This module provides a pass to replacing the following statements with -//! [`Nop`]s +//! This module provides a pass that removes parts of MIR that are no longer relevant after +//! analysis phase and borrowck. In particular, it removes false edges, user type annotations and +//! replaces following statements with [`Nop`]s: //! //! - [`AscribeUserType`] //! - [`FakeRead`] //! - [`Assign`] statements with a [`Shallow`] borrow //! -//! The `CleanFakeReadsAndBorrows` "pass" is actually implemented as two -//! traversals (aka visits) of the input MIR. The first traversal, -//! `DeleteAndRecordFakeReads`, deletes the fake reads and finds the -//! temporaries read by [`ForMatchGuard`] reads, and `DeleteFakeBorrows` -//! deletes the initialization of those temporaries. -//! //! [`AscribeUserType`]: rustc_middle::mir::StatementKind::AscribeUserType -//! [`Shallow`]: rustc_middle::mir::BorrowKind::Shallow -//! [`FakeRead`]: rustc_middle::mir::StatementKind::FakeRead //! [`Assign`]: rustc_middle::mir::StatementKind::Assign -//! [`ForMatchGuard`]: rustc_middle::mir::FakeReadCause::ForMatchGuard +//! [`FakeRead`]: rustc_middle::mir::StatementKind::FakeRead //! [`Nop`]: rustc_middle::mir::StatementKind::Nop +//! [`Shallow`]: rustc_middle::mir::BorrowKind::Shallow use crate::MirPass; -use rustc_middle::mir::visit::MutVisitor; -use rustc_middle::mir::{Body, BorrowKind, Location, Rvalue}; -use rustc_middle::mir::{Statement, StatementKind}; +use rustc_middle::mir::{Body, BorrowKind, Rvalue, StatementKind, TerminatorKind}; use rustc_middle::ty::TyCtxt; -pub struct CleanupNonCodegenStatements; +pub struct CleanupPostBorrowck; -pub struct DeleteNonCodegenStatements<'tcx> { - tcx: TyCtxt<'tcx>, -} +impl<'tcx> MirPass<'tcx> for CleanupPostBorrowck { + fn run_pass(&self, _tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) { + for basic_block in body.basic_blocks.as_mut() { + for statement in basic_block.statements.iter_mut() { + match statement.kind { + StatementKind::AscribeUserType(..) + | StatementKind::Assign(box (_, Rvalue::Ref(_, BorrowKind::Shallow, _))) + | StatementKind::FakeRead(..) => statement.make_nop(), + _ => (), + } + } + let terminator = basic_block.terminator_mut(); + match terminator.kind { + TerminatorKind::FalseEdge { real_target, .. } + | TerminatorKind::FalseUnwind { real_target, .. } => { + terminator.kind = TerminatorKind::Goto { target: real_target }; + } + _ => {} + } + } -impl<'tcx> MirPass<'tcx> for CleanupNonCodegenStatements { - fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) { - let mut delete = DeleteNonCodegenStatements { tcx }; - delete.visit_body_preserves_cfg(body); body.user_type_annotations.raw.clear(); for decl in &mut body.local_decls { @@ -41,19 +46,3 @@ impl<'tcx> MirPass<'tcx> for CleanupNonCodegenStatements { } } } - -impl<'tcx> MutVisitor<'tcx> for DeleteNonCodegenStatements<'tcx> { - fn tcx(&self) -> TyCtxt<'tcx> { - self.tcx - } - - fn visit_statement(&mut self, statement: &mut Statement<'tcx>, location: Location) { - match statement.kind { - StatementKind::AscribeUserType(..) - | StatementKind::Assign(box (_, Rvalue::Ref(_, BorrowKind::Shallow, _))) - | StatementKind::FakeRead(..) => statement.make_nop(), - _ => (), - } - self.super_statement(statement, location); - } -} diff --git a/compiler/rustc_mir_transform/src/const_prop.rs b/compiler/rustc_mir_transform/src/const_prop.rs index e384cfe1659..5c45abc5a17 100644 --- a/compiler/rustc_mir_transform/src/const_prop.rs +++ b/compiler/rustc_mir_transform/src/const_prop.rs @@ -655,11 +655,7 @@ impl<'mir, 'tcx> ConstPropagator<'mir, 'tcx> { return None; } - if self.tcx.sess.mir_opt_level() >= 4 { - self.eval_rvalue_with_identities(rvalue, place) - } else { - self.use_ecx(|this| this.ecx.eval_rvalue_into_place(rvalue, place)) - } + self.eval_rvalue_with_identities(rvalue, place) } // Attempt to use algebraic identities to eliminate constant expressions diff --git a/compiler/rustc_mir_transform/src/coverage/graph.rs b/compiler/rustc_mir_transform/src/coverage/graph.rs index 782129be088..78d28f1ebab 100644 --- a/compiler/rustc_mir_transform/src/coverage/graph.rs +++ b/compiler/rustc_mir_transform/src/coverage/graph.rs @@ -282,9 +282,9 @@ impl graph::WithPredecessors for CoverageGraph { rustc_index::newtype_index! { /// A node in the control-flow graph of CoverageGraph. + #[debug_format = "bcb{}"] pub(super) struct BasicCoverageBlock { - DEBUG_FORMAT = "bcb{}", - const START_BCB = 0, + const START_BCB = 0; } } diff --git a/compiler/rustc_mir_transform/src/coverage/mod.rs b/compiler/rustc_mir_transform/src/coverage/mod.rs index 60481014488..1468afc6456 100644 --- a/compiler/rustc_mir_transform/src/coverage/mod.rs +++ b/compiler/rustc_mir_transform/src/coverage/mod.rs @@ -533,10 +533,10 @@ fn make_code_region( } } -fn fn_sig_and_body<'tcx>( - tcx: TyCtxt<'tcx>, +fn fn_sig_and_body( + tcx: TyCtxt<'_>, def_id: DefId, -) -> (Option<&'tcx rustc_hir::FnSig<'tcx>>, &'tcx rustc_hir::Body<'tcx>) { +) -> (Option<&rustc_hir::FnSig<'_>>, &rustc_hir::Body<'_>) { // FIXME(#79625): Consider improving MIR to provide the information needed, to avoid going back // to HIR for it. let hir_node = tcx.hir().get_if_local(def_id).expect("expected DefId is local"); diff --git a/compiler/rustc_mir_transform/src/coverage/query.rs b/compiler/rustc_mir_transform/src/coverage/query.rs index dc1e68b253e..3bd7f31b45d 100644 --- a/compiler/rustc_mir_transform/src/coverage/query.rs +++ b/compiler/rustc_mir_transform/src/coverage/query.rs @@ -136,7 +136,7 @@ fn coverageinfo<'tcx>(tcx: TyCtxt<'tcx>, instance_def: ty::InstanceDef<'tcx>) -> coverage_visitor.info } -fn covered_code_regions<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> Vec<&'tcx CodeRegion> { +fn covered_code_regions(tcx: TyCtxt<'_>, def_id: DefId) -> Vec<&CodeRegion> { let body = mir_body(tcx, def_id); body.basic_blocks .iter() @@ -163,7 +163,7 @@ fn is_inlined(body: &Body<'_>, statement: &Statement<'_>) -> bool { /// This function ensures we obtain the correct MIR for the given item irrespective of /// whether that means const mir or runtime mir. For `const fn` this opts for runtime /// mir. -fn mir_body<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> &'tcx mir::Body<'tcx> { +fn mir_body(tcx: TyCtxt<'_>, def_id: DefId) -> &mir::Body<'_> { let id = ty::WithOptConstParam::unknown(def_id); let def = ty::InstanceDef::Item(id); tcx.instance_mir(def) diff --git a/compiler/rustc_mir_transform/src/coverage/tests.rs b/compiler/rustc_mir_transform/src/coverage/tests.rs index eba6a2b34e4..fa7f22303a8 100644 --- a/compiler/rustc_mir_transform/src/coverage/tests.rs +++ b/compiler/rustc_mir_transform/src/coverage/tests.rs @@ -169,7 +169,7 @@ impl<'tcx> MockBlocks<'tcx> { } } -fn debug_basic_blocks<'tcx>(mir_body: &Body<'tcx>) -> String { +fn debug_basic_blocks(mir_body: &Body<'_>) -> String { format!( "{:?}", mir_body diff --git a/compiler/rustc_mir_transform/src/dead_store_elimination.rs b/compiler/rustc_mir_transform/src/dead_store_elimination.rs index 42c580c63f0..09546330cec 100644 --- a/compiler/rustc_mir_transform/src/dead_store_elimination.rs +++ b/compiler/rustc_mir_transform/src/dead_store_elimination.rs @@ -71,7 +71,7 @@ pub fn eliminate<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>, borrowed: &BitS bbs[block].statements[statement_index].make_nop(); } - crate::simplify::SimplifyLocals.run_pass(tcx, body) + crate::simplify::simplify_locals(body, tcx) } pub struct DeadStoreElimination; diff --git a/compiler/rustc_mir_transform/src/deduce_param_attrs.rs b/compiler/rustc_mir_transform/src/deduce_param_attrs.rs index 92f1fff6beb..ddab7bbb2e3 100644 --- a/compiler/rustc_mir_transform/src/deduce_param_attrs.rs +++ b/compiler/rustc_mir_transform/src/deduce_param_attrs.rs @@ -129,7 +129,7 @@ impl<'tcx> Visitor<'tcx> for DeduceReadOnly { } /// Returns true if values of a given type will never be passed indirectly, regardless of ABI. -fn type_will_always_be_passed_directly<'tcx>(ty: Ty<'tcx>) -> bool { +fn type_will_always_be_passed_directly(ty: Ty<'_>) -> bool { matches!( ty.kind(), ty::Bool diff --git a/compiler/rustc_mir_transform/src/dest_prop.rs b/compiler/rustc_mir_transform/src/dest_prop.rs index 74d8337653f..08e296a8371 100644 --- a/compiler/rustc_mir_transform/src/dest_prop.rs +++ b/compiler/rustc_mir_transform/src/dest_prop.rs @@ -658,7 +658,7 @@ impl WriteInfo { } } - fn add_place<'tcx>(&mut self, place: Place<'tcx>) { + fn add_place(&mut self, place: Place<'_>) { self.writes.push(place.local); } diff --git a/compiler/rustc_mir_transform/src/inline.rs b/compiler/rustc_mir_transform/src/inline.rs index 9d560f5c837..4219e6280eb 100644 --- a/compiler/rustc_mir_transform/src/inline.rs +++ b/compiler/rustc_mir_transform/src/inline.rs @@ -1,6 +1,7 @@ //! Inlining pass for MIR functions use crate::deref_separator::deref_finder; use rustc_attr::InlineAttr; +use rustc_hir::def_id::DefId; use rustc_index::bit_set::BitSet; use rustc_index::vec::Idx; use rustc_middle::middle::codegen_fn_attrs::{CodegenFnAttrFlags, CodegenFnAttrs}; @@ -27,6 +28,8 @@ const RESUME_PENALTY: usize = 45; const UNKNOWN_SIZE_COST: usize = 10; +const TOP_DOWN_DEPTH_LIMIT: usize = 5; + pub struct Inline; #[derive(Copy, Clone, Debug)] @@ -86,8 +89,13 @@ fn inline<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) -> bool { let param_env = tcx.param_env_reveal_all_normalized(def_id); - let mut this = - Inliner { tcx, param_env, codegen_fn_attrs: tcx.codegen_fn_attrs(def_id), changed: false }; + let mut this = Inliner { + tcx, + param_env, + codegen_fn_attrs: tcx.codegen_fn_attrs(def_id), + history: Vec::new(), + changed: false, + }; let blocks = BasicBlock::new(0)..body.basic_blocks.next_index(); this.process_blocks(body, blocks); this.changed @@ -98,12 +106,26 @@ struct Inliner<'tcx> { param_env: ParamEnv<'tcx>, /// Caller codegen attributes. codegen_fn_attrs: &'tcx CodegenFnAttrs, + /// Stack of inlined instances. + /// We only check the `DefId` and not the substs because we want to + /// avoid inlining cases of polymorphic recursion. + /// The number of `DefId`s is finite, so checking history is enough + /// to ensure that we do not loop endlessly while inlining. + history: Vec<DefId>, /// Indicates that the caller body has been modified. changed: bool, } impl<'tcx> Inliner<'tcx> { fn process_blocks(&mut self, caller_body: &mut Body<'tcx>, blocks: Range<BasicBlock>) { + // How many callsites in this body are we allowed to inline? We need to limit this in order + // to prevent super-linear growth in MIR size + let inline_limit = match self.history.len() { + 0 => usize::MAX, + 1..=TOP_DOWN_DEPTH_LIMIT => 1, + _ => return, + }; + let mut inlined_count = 0; for bb in blocks { let bb_data = &caller_body[bb]; if bb_data.is_cleanup { @@ -122,12 +144,16 @@ impl<'tcx> Inliner<'tcx> { debug!("not-inlined {} [{}]", callsite.callee, reason); continue; } - Ok(_) => { + Ok(new_blocks) => { debug!("inlined {}", callsite.callee); self.changed = true; - // We could process the blocks returned by `try_inlining` here. However, that - // leads to exponential compile times due to the top-down nature of this kind - // of inlining. + inlined_count += 1; + if inlined_count == inline_limit { + return; + } + self.history.push(callsite.callee.def_id()); + self.process_blocks(caller_body, new_blocks); + self.history.pop(); } } } @@ -289,7 +315,7 @@ impl<'tcx> Inliner<'tcx> { ) -> Option<CallSite<'tcx>> { // Only consider direct calls to functions let terminator = bb_data.terminator(); - if let TerminatorKind::Call { ref func, target, .. } = terminator.kind { + if let TerminatorKind::Call { ref func, target, fn_span, .. } = terminator.kind { let func_ty = func.ty(caller_body, self.tcx); if let ty::FnDef(def_id, substs) = *func_ty.kind() { // To resolve an instance its substs have to be fully normalized. @@ -301,15 +327,14 @@ impl<'tcx> Inliner<'tcx> { return None; } + if self.history.contains(&callee.def_id()) { + return None; + } + let fn_sig = self.tcx.bound_fn_sig(def_id).subst(self.tcx, substs); + let source_info = SourceInfo { span: fn_span, ..terminator.source_info }; - return Some(CallSite { - callee, - fn_sig, - block: bb, - target, - source_info: terminator.source_info, - }); + return Some(CallSite { callee, fn_sig, block: bb, target, source_info }); } } diff --git a/compiler/rustc_mir_transform/src/lib.rs b/compiler/rustc_mir_transform/src/lib.rs index 93200b28830..16b8a901f36 100644 --- a/compiler/rustc_mir_transform/src/lib.rs +++ b/compiler/rustc_mir_transform/src/lib.rs @@ -77,8 +77,6 @@ mod match_branches; mod multiple_return_terminators; mod normalize_array_len; mod nrvo; -// This pass is public to allow external drivers to perform MIR cleanup -pub mod remove_false_edges; mod remove_noop_landing_pads; mod remove_storage_markers; mod remove_uninit_drops; @@ -268,10 +266,7 @@ fn mir_const_qualif(tcx: TyCtxt<'_>, def: ty::WithOptConstParam<LocalDefId>) -> /// Make MIR ready for const evaluation. This is run on all MIR, not just on consts! /// FIXME(oli-obk): it's unclear whether we still need this phase (and its corresponding query). /// We used to have this for pre-miri MIR based const eval. -fn mir_const<'tcx>( - tcx: TyCtxt<'tcx>, - def: ty::WithOptConstParam<LocalDefId>, -) -> &'tcx Steal<Body<'tcx>> { +fn mir_const(tcx: TyCtxt<'_>, def: ty::WithOptConstParam<LocalDefId>) -> &Steal<Body<'_>> { if let Some(def) = def.try_upgrade(tcx) { return tcx.mir_const(def); } @@ -310,10 +305,10 @@ fn mir_const<'tcx>( } /// Compute the main MIR body and the list of MIR bodies of the promoteds. -fn mir_promoted<'tcx>( - tcx: TyCtxt<'tcx>, +fn mir_promoted( + tcx: TyCtxt<'_>, def: ty::WithOptConstParam<LocalDefId>, -) -> (&'tcx Steal<Body<'tcx>>, &'tcx Steal<IndexVec<Promoted, Body<'tcx>>>) { +) -> (&Steal<Body<'_>>, &Steal<IndexVec<Promoted, Body<'_>>>) { if let Some(def) = def.try_upgrade(tcx) { return tcx.mir_promoted(def); } @@ -352,7 +347,7 @@ fn mir_promoted<'tcx>( } /// Compute the MIR that is used during CTFE (and thus has no optimizations run on it) -fn mir_for_ctfe<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> &'tcx Body<'tcx> { +fn mir_for_ctfe(tcx: TyCtxt<'_>, def_id: DefId) -> &Body<'_> { let did = def_id.expect_local(); if let Some(def) = ty::WithOptConstParam::try_lookup(did, tcx) { tcx.mir_for_ctfe_of_const_arg(def) @@ -366,10 +361,7 @@ fn mir_for_ctfe<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> &'tcx Body<'tcx> { /// we'd get cycle errors with `mir_for_ctfe`, because typeck would need to typeck /// the const parameter while type checking the main body, which in turn would try /// to type check the main body again. -fn mir_for_ctfe_of_const_arg<'tcx>( - tcx: TyCtxt<'tcx>, - (did, param_did): (LocalDefId, DefId), -) -> &'tcx Body<'tcx> { +fn mir_for_ctfe_of_const_arg(tcx: TyCtxt<'_>, (did, param_did): (LocalDefId, DefId)) -> &Body<'_> { tcx.arena.alloc(inner_mir_for_ctfe( tcx, ty::WithOptConstParam { did, const_param_did: Some(param_did) }, @@ -426,10 +418,10 @@ fn inner_mir_for_ctfe(tcx: TyCtxt<'_>, def: ty::WithOptConstParam<LocalDefId>) - /// Obtain just the main MIR (no promoteds) and run some cleanups on it. This also runs /// mir borrowck *before* doing so in order to ensure that borrowck can be run and doesn't /// end up missing the source MIR due to stealing happening. -fn mir_drops_elaborated_and_const_checked<'tcx>( - tcx: TyCtxt<'tcx>, +fn mir_drops_elaborated_and_const_checked( + tcx: TyCtxt<'_>, def: ty::WithOptConstParam<LocalDefId>, -) -> &'tcx Steal<Body<'tcx>> { +) -> &Steal<Body<'_>> { if let Some(def) = def.try_upgrade(tcx) { return tcx.mir_drops_elaborated_and_const_checked(def); } @@ -494,10 +486,9 @@ fn run_analysis_to_runtime_passes<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx> /// After this series of passes, no lifetime analysis based on borrowing can be done. fn run_analysis_cleanup_passes<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) { let passes: &[&dyn MirPass<'tcx>] = &[ - &remove_false_edges::RemoveFalseEdges, + &cleanup_post_borrowck::CleanupPostBorrowck, &simplify_branches::SimplifyConstCondition::new("initial"), &remove_noop_landing_pads::RemoveNoopLandingPads, - &cleanup_post_borrowck::CleanupNonCodegenStatements, &simplify::SimplifyCfg::new("early-opt"), &deref_separator::Derefer, ]; @@ -533,11 +524,8 @@ fn run_runtime_lowering_passes<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) { /// Returns the sequence of passes that do the initial cleanup of runtime MIR. fn run_runtime_cleanup_passes<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) { - let passes: &[&dyn MirPass<'tcx>] = &[ - &elaborate_box_derefs::ElaborateBoxDerefs, - &lower_intrinsics::LowerIntrinsics, - &simplify::SimplifyCfg::new("elaborate-drops"), - ]; + let passes: &[&dyn MirPass<'tcx>] = + &[&lower_intrinsics::LowerIntrinsics, &simplify::SimplifyCfg::new("elaborate-drops")]; pm::run_passes(tcx, body, passes, Some(MirPhase::Runtime(RuntimePhase::PostCleanup))); } @@ -569,6 +557,7 @@ fn run_optimization_passes<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) { &multiple_return_terminators::MultipleReturnTerminators, &instcombine::InstCombine, &separate_const_switch::SeparateConstSwitch, + &simplify::SimplifyLocals::new("before-const-prop"), // // FIXME(#70073): This pass is responsible for both optimization as well as some lints. &const_prop::ConstProp, @@ -587,7 +576,7 @@ fn run_optimization_passes<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) { &o1(remove_noop_landing_pads::RemoveNoopLandingPads), &o1(simplify::SimplifyCfg::new("final")), &nrvo::RenameReturnPlace, - &simplify::SimplifyLocals, + &simplify::SimplifyLocals::new("final"), &multiple_return_terminators::MultipleReturnTerminators, &deduplicate_blocks::DeduplicateBlocks, // Some cleanup necessary at least for LLVM and potentially other codegen backends. @@ -600,7 +589,7 @@ fn run_optimization_passes<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) { } /// Optimize the MIR and prepare it for codegen. -fn optimized_mir<'tcx>(tcx: TyCtxt<'tcx>, did: DefId) -> &'tcx Body<'tcx> { +fn optimized_mir(tcx: TyCtxt<'_>, did: DefId) -> &Body<'_> { let did = did.expect_local(); assert_eq!(ty::WithOptConstParam::try_lookup(did, tcx), None); tcx.arena.alloc(inner_optimized_mir(tcx, did)) @@ -637,10 +626,10 @@ fn inner_optimized_mir(tcx: TyCtxt<'_>, did: LocalDefId) -> Body<'_> { /// Fetch all the promoteds of an item and prepare their MIR bodies to be ready for /// constant evaluation once all substitutions become known. -fn promoted_mir<'tcx>( - tcx: TyCtxt<'tcx>, +fn promoted_mir( + tcx: TyCtxt<'_>, def: ty::WithOptConstParam<LocalDefId>, -) -> &'tcx IndexVec<Promoted, Body<'tcx>> { +) -> &IndexVec<Promoted, Body<'_>> { if tcx.is_constructor(def.did.to_def_id()) { return tcx.arena.alloc(IndexVec::new()); } diff --git a/compiler/rustc_mir_transform/src/normalize_array_len.rs b/compiler/rustc_mir_transform/src/normalize_array_len.rs index a159e617178..1708b287e56 100644 --- a/compiler/rustc_mir_transform/src/normalize_array_len.rs +++ b/compiler/rustc_mir_transform/src/normalize_array_len.rs @@ -16,7 +16,8 @@ pub struct NormalizeArrayLen; impl<'tcx> MirPass<'tcx> for NormalizeArrayLen { fn is_enabled(&self, sess: &rustc_session::Session) -> bool { - sess.mir_opt_level() >= 4 + // See #105929 + sess.mir_opt_level() >= 4 && sess.opts.unstable_opts.unsound_mir_opts } fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) { diff --git a/compiler/rustc_mir_transform/src/remove_false_edges.rs b/compiler/rustc_mir_transform/src/remove_false_edges.rs deleted file mode 100644 index 71f5ccf7e24..00000000000 --- a/compiler/rustc_mir_transform/src/remove_false_edges.rs +++ /dev/null @@ -1,29 +0,0 @@ -use rustc_middle::mir::{Body, TerminatorKind}; -use rustc_middle::ty::TyCtxt; - -use crate::MirPass; - -/// Removes `FalseEdge` and `FalseUnwind` terminators from the MIR. -/// -/// These are only needed for borrow checking, and can be removed afterwards. -/// -/// FIXME: This should probably have its own MIR phase. -pub struct RemoveFalseEdges; - -impl<'tcx> MirPass<'tcx> for RemoveFalseEdges { - fn run_pass(&self, _: TyCtxt<'tcx>, body: &mut Body<'tcx>) { - for block in body.basic_blocks_mut() { - let terminator = block.terminator_mut(); - terminator.kind = match terminator.kind { - TerminatorKind::FalseEdge { real_target, .. } => { - TerminatorKind::Goto { target: real_target } - } - TerminatorKind::FalseUnwind { real_target, .. } => { - TerminatorKind::Goto { target: real_target } - } - - _ => continue, - } - } - } -} diff --git a/compiler/rustc_mir_transform/src/shim.rs b/compiler/rustc_mir_transform/src/shim.rs index f8b55c86287..dace540fa29 100644 --- a/compiler/rustc_mir_transform/src/shim.rs +++ b/compiler/rustc_mir_transform/src/shim.rs @@ -174,9 +174,36 @@ fn build_drop_shim<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId, ty: Option<Ty<'tcx>>) let mut body = new_body(source, blocks, local_decls_for_sig(&sig, span), sig.inputs().len(), span); + // The first argument (index 0), but add 1 for the return value. + let mut dropee_ptr = Place::from(Local::new(1 + 0)); + if tcx.sess.opts.unstable_opts.mir_emit_retag { + // We want to treat the function argument as if it was passed by `&mut`. As such, we + // generate + // ``` + // temp = &mut *arg; + // Retag(temp, FnEntry) + // ``` + // It's important that we do this first, before anything that depends on `dropee_ptr` + // has been put into the body. + let reborrow = Rvalue::Ref( + tcx.lifetimes.re_erased, + BorrowKind::Mut { allow_two_phase_borrow: false }, + tcx.mk_place_deref(dropee_ptr), + ); + let ref_ty = reborrow.ty(body.local_decls(), tcx); + dropee_ptr = body.local_decls.push(LocalDecl::new(ref_ty, span)).into(); + let new_statements = [ + StatementKind::Assign(Box::new((dropee_ptr, reborrow))), + StatementKind::Retag(RetagKind::FnEntry, Box::new(dropee_ptr)), + ]; + for s in new_statements { + body.basic_blocks_mut()[START_BLOCK] + .statements + .push(Statement { source_info, kind: s }); + } + } + if ty.is_some() { - // The first argument (index 0), but add 1 for the return value. - let dropee_ptr = Place::from(Local::new(1 + 0)); let patch = { let param_env = tcx.param_env_reveal_all_normalized(def_id); let mut elaborator = diff --git a/compiler/rustc_mir_transform/src/simplify.rs b/compiler/rustc_mir_transform/src/simplify.rs index 8212a7b523b..8f6abe7a912 100644 --- a/compiler/rustc_mir_transform/src/simplify.rs +++ b/compiler/rustc_mir_transform/src/simplify.rs @@ -379,9 +379,21 @@ fn save_unreachable_coverage( )); } -pub struct SimplifyLocals; +pub struct SimplifyLocals { + label: String, +} + +impl SimplifyLocals { + pub fn new(label: &str) -> SimplifyLocals { + SimplifyLocals { label: format!("SimplifyLocals-{}", label) } + } +} impl<'tcx> MirPass<'tcx> for SimplifyLocals { + fn name(&self) -> &str { + &self.label + } + fn is_enabled(&self, sess: &rustc_session::Session) -> bool { sess.mir_opt_level() > 0 } @@ -557,6 +569,7 @@ fn remove_unused_definitions(used_locals: &mut UsedLocals, body: &mut Body<'_>) StatementKind::SetDiscriminant { ref place, .. } | StatementKind::Deinit(ref place) => used_locals.is_used(place.local), + StatementKind::Nop => false, _ => true, }; diff --git a/compiler/rustc_mir_transform/src/simplify_try.rs b/compiler/rustc_mir_transform/src/simplify_try.rs index baeb620ef24..e4f3ace9a93 100644 --- a/compiler/rustc_mir_transform/src/simplify_try.rs +++ b/compiler/rustc_mir_transform/src/simplify_try.rs @@ -532,7 +532,7 @@ struct VarField<'tcx> { } /// Match on `((_LOCAL as Variant).FIELD: TY)`. -fn match_variant_field_place<'tcx>(place: Place<'tcx>) -> Option<(Local, VarField<'tcx>)> { +fn match_variant_field_place(place: Place<'_>) -> Option<(Local, VarField<'_>)> { match place.as_ref() { PlaceRef { local, |