//! Inlining pass for MIR functions use rustc_attr as attr; use rustc_index::bit_set::BitSet; use rustc_index::vec::{Idx, IndexVec}; use rustc_middle::middle::codegen_fn_attrs::{CodegenFnAttrFlags, CodegenFnAttrs}; use rustc_middle::mir::visit::*; use rustc_middle::mir::*; use rustc_middle::ty::subst::Subst; use rustc_middle::ty::{self, ConstKind, Instance, InstanceDef, ParamEnv, Ty, TyCtxt}; use rustc_target::spec::abi::Abi; use super::simplify::{remove_dead_blocks, CfgSimplifier}; use crate::transform::MirPass; use std::collections::VecDeque; use std::iter; const DEFAULT_THRESHOLD: usize = 50; const HINT_THRESHOLD: usize = 100; const INSTR_COST: usize = 5; const CALL_PENALTY: usize = 25; const LANDINGPAD_PENALTY: usize = 50; const RESUME_PENALTY: usize = 45; const UNKNOWN_SIZE_COST: usize = 10; pub struct Inline; #[derive(Copy, Clone, Debug)] struct CallSite<'tcx> { callee: Instance<'tcx>, bb: BasicBlock, source_info: SourceInfo, } impl<'tcx> MirPass<'tcx> for Inline { fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) { if tcx.sess.opts.debugging_opts.mir_opt_level >= 2 { if tcx.sess.opts.debugging_opts.instrument_coverage { // The current implementation of source code coverage injects code region counters // into the MIR, and assumes a 1-to-1 correspondence between MIR and source-code- // based function. debug!("function inlining is disabled when compiling with `instrument_coverage`"); } else { Inliner { tcx, param_env: tcx.param_env_reveal_all_normalized(body.source.def_id()), codegen_fn_attrs: tcx.codegen_fn_attrs(body.source.def_id()), } .run_pass(body); } } } } struct Inliner<'tcx> { tcx: TyCtxt<'tcx>, param_env: ParamEnv<'tcx>, codegen_fn_attrs: &'tcx CodegenFnAttrs, } impl Inliner<'tcx> { fn run_pass(&self, caller_body: &mut Body<'tcx>) { // Keep a queue of callsites to try inlining on. We take // advantage of the fact that queries detect cycles here to // allow us to try and fetch the fully optimized MIR of a // call; if it succeeds, we can inline it and we know that // they do not call us. Otherwise, we just don't try to // inline. // // We use a queue so that we inline "broadly" before we inline // in depth. It is unclear if this is the best heuristic, // really, but that's true of all the heuristics in this // file. =) let mut callsites = VecDeque::new(); let def_id = caller_body.source.def_id(); // Only do inlining into fn bodies. let self_hir_id = self.tcx.hir().local_def_id_to_hir_id(def_id.expect_local()); if self.tcx.hir().body_owner_kind(self_hir_id).is_fn_or_closure() && caller_body.source.promoted.is_none() { for (bb, bb_data) in caller_body.basic_blocks().iter_enumerated() { if let Some(callsite) = self.get_valid_function_call(bb, bb_data, caller_body) { callsites.push_back(callsite); } } } else { return; } let mut local_change; let mut changed = false; loop { local_change = false; while let Some(callsite) = callsites.pop_front() { debug!("checking whether to inline callsite {:?}", callsite); if let InstanceDef::Item(_) = callsite.callee.def { if !self.tcx.is_mir_available(callsite.callee.def_id()) { debug!( "checking whether to inline callsite {:?} - MIR unavailable", callsite, ); continue; } } let callee_body = if let Some(callee_def_id) = callsite.callee.def_id().as_local() { let callee_hir_id = self.tcx.hir().local_def_id_to_hir_id(callee_def_id); // Avoid a cycle here by only using `instance_mir` only if we have // a lower `HirId` than the callee. This ensures that the callee will // not inline us. This trick only works without incremental compilation. // So don't do it if that is enabled. Also avoid inlining into generators, // since their `optimized_mir` is used for layout computation, which can // create a cycle, even when no attempt is made to inline the function // in the other direction. if !self.tcx.dep_graph.is_fully_enabled() && self_hir_id < callee_hir_id && caller_body.generator_kind.is_none() { self.tcx.instance_mir(callsite.callee.def) } else { continue; } } else { // This cannot result in a cycle since the callee MIR is from another crate // and is already optimized. self.tcx.instance_mir(callsite.callee.def) }; let callee_body: &Body<'tcx> = &*callee_body; let callee_body = if self.consider_optimizing(callsite, callee_body) { self.tcx.subst_and_normalize_erasing_regions( &callsite.callee.substs, self.param_env, callee_body, ) } else { continue; }; // Copy only unevaluated constants from the callee_body into the caller_body. // Although we are only pushing `ConstKind::Unevaluated` consts to // `required_consts`, here we may not only have `ConstKind::Unevaluated` // because we are calling `subst_and_normalize_erasing_regions`. caller_body.required_consts.extend( callee_body.required_consts.iter().copied().filter(|&constant| { matches!(constant.literal.val, ConstKind::Unevaluated(_, _, _)) }), ); let start = caller_body.basic_blocks().len(); debug!("attempting to inline callsite {:?} - body={:?}", callsite, callee_body); if !self.inline_call(callsite, caller_body, callee_body) { debug!("attempting to inline callsite {:?} - failure", callsite); continue; } debug!("attempting to inline callsite {:?} - success", callsite); // Add callsites from inlined function for (bb, bb_data) in caller_body.basic_blocks().iter_enumerated().skip(start) { if let Some(new_callsite) = self.get_valid_function_call(bb, bb_data, caller_body) { // Don't inline the same function multiple times. if callsite.callee != new_callsite.callee { callsites.push_back(new_callsite); } } } local_change = true; changed = true; } if !local_change { break; } } // Simplify if we inlined anything. if changed { debug!("running simplify cfg on {:?}", caller_body.source); CfgSimplifier::new(caller_body).simplify(); remove_dead_blocks(caller_body); } } fn get_valid_function_call( &self, bb: BasicBlock, bb_data: &BasicBlockData<'tcx>, caller_body: &Body<'tcx>, ) -> Option> { // Don't inline calls that are in cleanup blocks. if bb_data.is_cleanup { return None; } // Only consider direct calls to functions let terminator = bb_data.terminator(); if let TerminatorKind::Call { func: ref op, .. } = terminator.kind { if let ty::FnDef(callee_def_id, substs) = *op.ty(caller_body, self.tcx).kind() { // To resolve an instance its substs have to be fully normalized, so // we do this here. let normalized_substs = self.tcx.normalize_erasing_regions(self.param_env, substs); let callee = Instance::resolve(self.tcx, self.param_env, callee_def_id, normalized_substs) .ok() .flatten()?; if let InstanceDef::Virtual(..) | InstanceDef::Intrinsic(_) = callee.def { return None; } return Some(CallSite { callee, bb, source_info: terminator.source_info }); } } None } fn consider_optimizing(&self, callsite: CallSite<'tcx>, callee_body: &Body<'tcx>) -> bool { debug!("consider_optimizing({:?})", callsite); self.should_inline(callsite, callee_body) && self.tcx.consider_optimizing(|| { format!("Inline {:?} into {:?}", callee_body.span, callsite) }) } fn should_inline(&self, callsite: CallSite<'tcx>, callee_body: &Body<'tcx>) -> bool { debug!("should_inline({:?})", callsite); let tcx = self.tcx; // Cannot inline generators which haven't been transformed yet if callee_body.yield_ty.is_some() { debug!(" yield ty present - not inlining"); return false; } let codegen_fn_attrs = tcx.codegen_fn_attrs(callsite.callee.def_id()); let self_features = &self.codegen_fn_attrs.target_features; let callee_features = &codegen_fn_attrs.target_features; if callee_features.iter().any(|feature| !self_features.contains(feature)) { debug!("`callee has extra target features - not inlining"); return false; } let self_no_sanitize = self.codegen_fn_attrs.no_sanitize & self.tcx.sess.opts.debugging_opts.sanitizer; let callee_no_sanitize = codegen_fn_attrs.no_sanitize & self.tcx.sess.opts.debugging_opts.sanitizer; if self_no_sanitize != callee_no_sanitize { debug!("`callee has incompatible no_sanitize attribute - not inlining"); return false; } let hinted = match codegen_fn_attrs.inline { // Just treat inline(always) as a hint for now, // there are cases that prevent inlining that we // need to check for first. attr::InlineAttr::Always => true, attr::InlineAttr::Never => { debug!("`#[inline(never)]` present - not inlining"); return false; } attr::InlineAttr::Hint => true, attr::InlineAttr::None => false, }; // Only inline local functions if they would be eligible for cross-crate // inlining. This is to ensure that the final crate doesn't have MIR that // reference unexported symbols if callsite.callee.def_id().is_local() { if callsite.callee.substs.non_erasable_generics().count() == 0 && !hinted { debug!(" callee is an exported function - not inlining"); return false; } } let mut threshold = if hinted { HINT_THRESHOLD } else { DEFAULT_THRESHOLD }; // Significantly lower the threshold for inlining cold functions if codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::COLD) { threshold /= 5; } // Give a bonus functions with a small number of blocks, // We normally have two or three blocks for even // very small functions. if callee_body.basic_blocks().len() <= 3 { threshold += threshold / 4; } debug!(" final inline threshold = {}", threshold); // FIXME: Give a bonus to functions with only a single caller let mut first_block = true; let mut cost = 0; // Traverse the MIR manually so we can account for the effects of // inlining on the CFG. let mut work_list = vec![START_BLOCK]; let mut visited = BitSet::new_empty(callee_body.basic_blocks().len()); while let Some(bb) = work_list.pop() { if !visited.insert(bb.index()) { continue; } let blk = &callee_body.basic_blocks()[bb]; for stmt in &blk.statements { // Don't count StorageLive/StorageDead in the inlining cost. match stmt.kind { StatementKind::StorageLive(_) | StatementKind::StorageDead(_) | StatementKind::Nop => {} _ => cost += INSTR_COST, } } let term = blk.terminator(); let mut is_drop = false; match term.kind { TerminatorKind::Drop { ref place, target, unwind } | TerminatorKind::DropAndReplace { ref place, target, unwind, .. } => { is_drop = true; work_list.push(target); // If the place doesn't actually need dropping, treat it like // a regular goto. let ty = place.ty(callee_body, tcx).subst(tcx, callsite.callee.substs).ty; if ty.needs_drop(tcx, self.param_env) { cost += CALL_PENALTY; if let Some(unwind) = unwind { cost += LANDINGPAD_PENALTY; work_list.push(unwind); } } else { cost += INSTR_COST; } } TerminatorKind::Unreachable | TerminatorKind::Call { destination: None, .. } if first_block => { // If the function always diverges, don't inline // unless the cost is zero threshold = 0; } TerminatorKind::Call { func: Operand::Constant(ref f), cleanup, .. } => { if let ty::FnDef(def_id, _) = *f.literal.ty.kind() { // Don't give intrinsics the extra penalty for calls let f = tcx.fn_sig(def_id); if f.abi() == Abi::RustIntrinsic || f.abi() == Abi::PlatformIntrinsic { cost += INSTR_COST; } else { cost += CALL_PENALTY; } } else { cost += CALL_PENALTY; } if cleanup.is_some() { cost += LANDINGPAD_PENALTY; } } TerminatorKind::Assert { cleanup, .. } => { cost += CALL_PENALTY; if cleanup.is_some() { cost += LANDINGPAD_PENALTY; } } TerminatorKind::Resume => cost += RESUME_PENALTY, _ => cost += INSTR_COST, } if !is_drop { for &succ in term.successors() { work_list.push(succ); } } first_block = false; } // Count up the cost of local variables and temps, if we know the size // use that, otherwise we use a moderately-large dummy cost. let ptr_size = tcx.data_layout.pointer_size.bytes(); for v in callee_body.vars_and_temps_iter() { let v = &callee_body.local_decls[v]; let ty = v.ty.subst(tcx, callsite.callee.substs); // Cost of the var is the size in machine-words, if we know // it. if let Some(size) = type_size_of(tcx, self.param_env, ty) { cost += (size / ptr_size) as usize; } else { cost += UNKNOWN_SIZE_COST; } } if let attr::InlineAttr::Always = codegen_fn_attrs.inline { debug!("INLINING {:?} because inline(always) [cost={}]", callsite, cost); true } else { if cost <= threshold { debug!("INLINING {:?} [cost={} <= threshold={}]", callsite, cost, threshold); true } else { debug!("NOT inlining {:?} [cost={} > threshold={}]", callsite, cost, threshold); false } } } fn inline_call( &self, callsite: CallSite<'tcx>, caller_body: &mut Body<'tcx>, mut callee_body: Body<'tcx>, ) -> bool { let terminator = caller_body[callsite.bb].terminator.take().unwrap(); match terminator.kind { // FIXME: Handle inlining of diverging calls TerminatorKind::Call { args, destination: Some(destination), cleanup, .. } => { debug!("inlined {:?} into {:?}", callsite.callee, caller_body.source); // If the call is something like `a[*i] = f(i)`, where // `i : &mut usize`, then just duplicating the `a[*i]` // Place could result in two different locations if `f` // writes to `i`. To prevent this we need to create a temporary // borrow of the place and pass the destination as `*temp` instead. fn dest_needs_borrow(place: Place<'_>) -> bool { for elem in place.projection.iter() { match elem { ProjectionElem::Deref | ProjectionElem::Index(_) => return true, _ => {} } } false } let dest = if dest_needs_borrow(destination.0) { debug!("creating temp for return destination"); let dest = Rvalue::Ref( self.tcx.lifetimes.re_erased, BorrowKind::Mut { allow_two_phase_borrow: false }, destination.0, ); let ty = dest.ty(caller_body, self.tcx); let temp = LocalDecl::new(ty, callsite.source_info.span); let tmp = caller_body.local_decls.push(temp); let tmp = Place::from(tmp); let stmt = Statement { source_info: callsite.source_info, kind: StatementKind::Assign(box (tmp, dest)), }; caller_body[callsite.bb].statements.push(stmt); self.tcx.mk_place_deref(tmp) } else { destination.0 }; let return_block = destination.1; // Copy the arguments if needed. let args: Vec<_> = self.make_call_args(args, &callsite, caller_body, return_block); let bb_len = caller_body.basic_blocks().len(); let mut integrator = Integrator { block_idx: bb_len, args: &args, local_map: IndexVec::with_capacity(callee_body.local_decls.len()), scope_map: IndexVec::with_capacity(callee_body.source_scopes.len()), destination: dest, return_block, cleanup_block: cleanup, in_cleanup_block: false, tcx: self.tcx, }; for mut scope in callee_body.source_scopes.iter().cloned() { // Map the callee scopes into the caller. // FIXME(eddyb) this may ICE if the scopes are out of order. scope.parent_scope = scope.parent_scope.map(|s| integrator.scope_map[s]); scope.inlined_parent_scope = scope.inlined_parent_scope.map(|s| integrator.scope_map[s]); if scope.parent_scope.is_none() { let callsite_scope = &caller_body.source_scopes[callsite.source_info.scope]; // Attach the outermost callee scope as a child of the callsite // scope, via the `parent_scope` and `inlined_parent_scope` chains. scope.parent_scope = Some(callsite.source_info.scope); assert_eq!(scope.inlined_parent_scope, None); scope.inlined_parent_scope = if callsite_scope.inlined.is_some() { Some(callsite.source_info.scope) } else { callsite_scope.inlined_parent_scope }; // Mark the outermost callee scope as an inlined one. assert_eq!(scope.inlined, None); scope.inlined = Some((callsite.callee, callsite.source_info.span)); } else if scope.inlined_parent_scope.is_none() { // Make it easy to find the scope with `inlined` set above. scope.inlined_parent_scope = Some(integrator.scope_map[OUTERMOST_SOURCE_SCOPE]); } let idx = caller_body.source_scopes.push(scope); integrator.scope_map.push(idx); } for loc in callee_body.vars_and_temps_iter() { let mut local = callee_body.local_decls[loc].clone(); local.source_info.scope = integrator.scope_map[local.source_info.scope]; let idx = caller_body.local_decls.push(local); integrator.local_map.push(idx); } for mut var_debug_info in callee_body.var_debug_info.drain(..) { integrator.visit_var_debug_info(&mut var_debug_info); caller_body.var_debug_info.push(var_debug_info); } for (bb, mut block) in callee_body.basic_blocks_mut().drain_enumerated(..) { integrator.visit_basic_block_data(bb, &mut block); caller_body.basic_blocks_mut().push(block); } let terminator = Terminator { source_info: callsite.source_info, kind: TerminatorKind::Goto { target: BasicBlock::new(bb_len) }, }; caller_body[callsite.bb].terminator = Some(terminator); true } kind => { caller_body[callsite.bb].terminator = Some(Terminator { source_info: terminator.source_info, kind }); false } } } fn make_call_args( &self, args: Vec>, callsite: &CallSite<'tcx>, caller_body: &mut Body<'tcx>, return_block: BasicBlock, ) -> Vec { let tcx = self.tcx; // There is a bit of a mismatch between the *caller* of a closure and the *callee*. // The caller provides the arguments wrapped up in a tuple: // // tuple_tmp = (a, b, c) // Fn::call(closure_ref, tuple_tmp) // // meanwhile the closure body expects the arguments (here, `a`, `b`, and `c`) // as distinct arguments. (This is the "rust-call" ABI hack.) Normally, codegen has // the job of unpacking this tuple. But here, we are codegen. =) So we want to create // a vector like // // [closure_ref, tuple_tmp.0, tuple_tmp.1, tuple_tmp.2] // // Except for one tiny wrinkle: we don't actually want `tuple_tmp.0`. It's more convenient // if we "spill" that into *another* temporary, so that we can map the argument // variable in the callee MIR directly to an argument variable on our side. // So we introduce temporaries like: // // tmp0 = tuple_tmp.0 // tmp1 = tuple_tmp.1 // tmp2 = tuple_tmp.2 // // and the vector is `[closure_ref, tmp0, tmp1, tmp2]`. // FIXME(eddyb) make this check for `"rust-call"` ABI combined with // `callee_body.spread_arg == None`, instead of special-casing closures. if tcx.is_closure(callsite.callee.def_id()) { let mut args = args.into_iter(); let self_ = self.create_temp_if_necessary( args.next().unwrap(), callsite, caller_body, return_block, ); let tuple = self.create_temp_if_necessary( args.next().unwrap(), callsite, caller_body, return_block, ); assert!(args.next().is_none()); let tuple = Place::from(tuple); let tuple_tys = if let ty::Tuple(s) = tuple.ty(caller_body, tcx).ty.kind() { s } else { bug!("Closure arguments are not passed as a tuple"); }; // The `closure_ref` in our example above. let closure_ref_arg = iter::once(self_); // The `tmp0`, `tmp1`, and `tmp2` in our example abonve. let tuple_tmp_args = tuple_tys.iter().enumerate().map(|(i, ty)| { // This is e.g., `tuple_tmp.0` in our example above. let tuple_field = Operand::Move(tcx.mk_place_field(tuple, Field::new(i), ty.expect_ty())); // Spill to a local to make e.g., `tmp0`. self.create_temp_if_necessary(tuple_field, callsite, caller_body, return_block) }); closure_ref_arg.chain(tuple_tmp_args).collect() } else { args.into_iter() .map(|a| self.create_temp_if_necessary(a, callsite, caller_body, return_block)) .collect() } } /// If `arg` is already a temporary, returns it. Otherwise, introduces a fresh /// temporary `T` and an instruction `T = arg`, and returns `T`. fn create_temp_if_necessary( &self, arg: Operand<'tcx>, callsite: &CallSite<'tcx>, caller_body: &mut Body<'tcx>, return_block: BasicBlock, ) -> Local { // FIXME: Analysis of the usage of the arguments to avoid // unnecessary temporaries. if let Operand::Move(place) = &arg { if let Some(local) = place.as_local() { if caller_body.local_kind(local) == LocalKind::Temp { // Reuse the operand if it's a temporary already return local; } } } debug!("creating temp for argument {:?}", arg); // Otherwise, create a temporary for the arg let arg = Rvalue::Use(arg); let ty = arg.ty(caller_body, self.tcx); let arg_tmp = LocalDecl::new(ty, callsite.source_info.span); let arg_tmp = caller_body.local_decls.push(arg_tmp); caller_body[callsite.bb].statements.push(Statement { source_info: callsite.source_info, kind: StatementKind::StorageLive(arg_tmp), }); caller_body[callsite.bb].statements.push(Statement { source_info: callsite.source_info, kind: StatementKind::Assign(box (Place::from(arg_tmp), arg)), }); caller_body[return_block].statements.insert( 0, Statement { source_info: callsite.source_info, kind: StatementKind::StorageDead(arg_tmp), }, ); arg_tmp } } fn type_size_of<'tcx>( tcx: TyCtxt<'tcx>, param_env: ty::ParamEnv<'tcx>, ty: Ty<'tcx>, ) -> Option { tcx.layout_of(param_env.and(ty)).ok().map(|layout| layout.size.bytes()) } /** * Integrator. * * Integrates blocks from the callee function into the calling function. * Updates block indices, references to locals and other control flow * stuff. */ struct Integrator<'a, 'tcx> { block_idx: usize, args: &'a [Local], local_map: IndexVec, scope_map: IndexVec, destination: Place<'tcx>, return_block: BasicBlock, cleanup_block: Option, in_cleanup_block: bool, tcx: TyCtxt<'tcx>, } impl<'a, 'tcx> Integrator<'a, 'tcx> { fn update_target(&self, tgt: BasicBlock) -> BasicBlock { let new = BasicBlock::new(tgt.index() + self.block_idx); debug!("updating target `{:?}`, new: `{:?}`", tgt, new); new } fn make_integrate_local(&self, local: Local) -> Local { if local == RETURN_PLACE { return self.destination.local; } let idx = local.index() - 1; if idx < self.args.len() { return self.args[idx]; } self.local_map[Local::new(idx - self.args.len())] } } impl<'a, 'tcx> MutVisitor<'tcx> for Integrator<'a, 'tcx> { fn tcx(&self) -> TyCtxt<'tcx> { self.tcx } fn visit_local(&mut self, local: &mut Local, _ctxt: PlaceContext, _location: Location) { *local = self.make_integrate_local(*local); } fn visit_place(&mut self, place: &mut Place<'tcx>, context: PlaceContext, location: Location) { // If this is the `RETURN_PLACE`, we need to rebase any projections onto it. let dest_proj_len = self.destination.projection.len(); if place.local == RETURN_PLACE && dest_proj_len > 0 { let mut projs = Vec::with_capacity(dest_proj_len + place.projection.len()); projs.extend(self.destination.projection); projs.extend(place.projection); place.projection = self.tcx.intern_place_elems(&*projs); } // Handles integrating any locals that occur in the base // or projections self.super_place(place, context, location) } fn visit_basic_block_data(&mut self, block: BasicBlock, data: &mut BasicBlockData<'tcx>) { self.in_cleanup_block = data.is_cleanup; self.super_basic_block_data(block, data); self.in_cleanup_block = false; } fn visit_retag(&mut self, kind: &mut RetagKind, place: &mut Place<'tcx>, loc: Location) { self.super_retag(kind, place, loc); // We have to patch all inlined retags to be aware that they are no longer // happening on function entry. if *kind == RetagKind::FnEntry { *kind = RetagKind::Default; } } fn visit_terminator(&mut self, terminator: &mut Terminator<'tcx>, loc: Location) { // Don't try to modify the implicit `_0` access on return (`return` terminators are // replaced down below anyways). if !matches!(terminator.kind, TerminatorKind::Return) { self.super_terminator(terminator, loc); } match terminator.kind { TerminatorKind::GeneratorDrop | TerminatorKind::Yield { .. } => bug!(), TerminatorKind::Goto { ref mut target } => { *target = self.update_target(*target); } TerminatorKind::SwitchInt { ref mut targets, .. } => { for tgt in targets.all_targets_mut() { *tgt = self.update_target(*tgt); } } TerminatorKind::Drop { ref mut target, ref mut unwind, .. } | TerminatorKind::DropAndReplace { ref mut target, ref mut unwind, .. } => { *target = self.update_target(*target); if let Some(tgt) = *unwind { *unwind = Some(self.update_target(tgt)); } else if !self.in_cleanup_block { // Unless this drop is in a cleanup block, add an unwind edge to // the original call's cleanup block *unwind = self.cleanup_block; } } TerminatorKind::Call { ref mut destination, ref mut cleanup, .. } => { if let Some((_, ref mut tgt)) = *destination { *tgt = self.update_target(*tgt); } if let Some(tgt) = *cleanup { *cleanup = Some(self.update_target(tgt)); } else if !self.in_cleanup_block { // Unless this call is in a cleanup block, add an unwind edge to // the original call's cleanup block *cleanup = self.cleanup_block; } } TerminatorKind::Assert { ref mut target, ref mut cleanup, .. } => { *target = self.update_target(*target); if let Some(tgt) = *cleanup { *cleanup = Some(self.update_target(tgt)); } else if !self.in_cleanup_block { // Unless this assert is in a cleanup block, add an unwind edge to // the original call's cleanup block *cleanup = self.cleanup_block; } } TerminatorKind::Return => { terminator.kind = TerminatorKind::Goto { target: self.return_block }; } TerminatorKind::Resume => { if let Some(tgt) = self.cleanup_block { terminator.kind = TerminatorKind::Goto { target: tgt } } } TerminatorKind::Abort => {} TerminatorKind::Unreachable => {} TerminatorKind::FalseEdge { ref mut real_target, ref mut imaginary_target } => { *real_target = self.update_target(*real_target); *imaginary_target = self.update_target(*imaginary_target); } TerminatorKind::FalseUnwind { real_target: _, unwind: _ } => // see the ordering of passes in the optimized_mir query. { bug!("False unwinds should have been removed before inlining") } TerminatorKind::InlineAsm { ref mut destination, .. } => { if let Some(ref mut tgt) = *destination { *tgt = self.update_target(*tgt); } } } } fn visit_source_scope(&mut self, scope: &mut SourceScope) { *scope = self.scope_map[*scope]; } }