| //! Inlining pass for MIR functions |
| |
| use rustc::hir::CodegenFnAttrFlags; |
| use rustc::hir::def_id::DefId; |
| |
| use rustc_index::bit_set::BitSet; |
| use rustc_index::vec::{Idx, IndexVec}; |
| |
| use rustc::mir::*; |
| use rustc::mir::visit::*; |
| use rustc::ty::{self, Instance, InstanceDef, ParamEnv, Ty, TyCtxt}; |
| use rustc::ty::subst::{Subst, SubstsRef}; |
| |
| use std::collections::VecDeque; |
| use std::iter; |
| use crate::transform::{MirPass, MirSource}; |
| use super::simplify::{remove_dead_blocks, CfgSimplifier}; |
| |
| use syntax::attr; |
| use rustc_target::spec::abi::Abi; |
| |
| const DEFAULT_THRESHOLD: usize = 50; |
| const HINT_THRESHOLD: usize = 100; |
| |
| const INSTR_COST: usize = 5; |
| const CALL_PENALTY: usize = 25; |
| |
| const UNKNOWN_SIZE_COST: usize = 10; |
| |
| pub struct Inline; |
| |
| #[derive(Copy, Clone, Debug)] |
| struct CallSite<'tcx> { |
| callee: DefId, |
| substs: SubstsRef<'tcx>, |
| bb: BasicBlock, |
| location: SourceInfo, |
| } |
| |
| impl<'tcx> MirPass<'tcx> for Inline { |
| fn run_pass(&self, tcx: TyCtxt<'tcx>, source: MirSource<'tcx>, body: &mut Body<'tcx>) { |
| if tcx.sess.opts.debugging_opts.mir_opt_level >= 2 { |
| Inliner { tcx, source }.run_pass(body); |
| } |
| } |
| } |
| |
| struct Inliner<'tcx> { |
| tcx: TyCtxt<'tcx>, |
| source: MirSource<'tcx>, |
| } |
| |
| 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 param_env = self.tcx.param_env(self.source.def_id()); |
| |
| // Only do inlining into fn bodies. |
| let id = self.tcx.hir().as_local_hir_id(self.source.def_id()).unwrap(); |
| if self.tcx.hir().body_owner_kind(id).is_fn_or_closure() |
| && self.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, |
| param_env) { |
| 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 !self.tcx.is_mir_available(callsite.callee) { |
| debug!("checking whether to inline callsite {:?} - MIR unavailable", callsite); |
| continue; |
| } |
| |
| let self_node_id = self.tcx.hir().as_local_node_id(self.source.def_id()).unwrap(); |
| let callee_node_id = self.tcx.hir().as_local_node_id(callsite.callee); |
| |
| let callee_body = if let Some(callee_node_id) = callee_node_id { |
| // Avoid a cycle here by only using `optimized_mir` only if we have |
| // a lower node id 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. |
| if !self.tcx.dep_graph.is_fully_enabled() |
| && self_node_id.as_u32() < callee_node_id.as_u32() { |
| self.tcx.optimized_mir(callsite.callee) |
| } else { |
| continue; |
| } |
| } else { |
| // This cannot result in a cycle since the callee MIR is from another crate |
| // and is already optimized. |
| self.tcx.optimized_mir(callsite.callee) |
| }; |
| |
| let callee_body = if self.consider_optimizing(callsite, callee_body) { |
| self.tcx.subst_and_normalize_erasing_regions( |
| &callsite.substs, |
| param_env, |
| callee_body, |
| ) |
| } else { |
| continue; |
| }; |
| |
| 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, |
| param_env) { |
| // 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 {:?}", self.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>, |
| param_env: ParamEnv<'tcx>, |
| ) -> Option<CallSite<'tcx>> { |
| // 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 { |
| let instance = Instance::resolve(self.tcx, |
| param_env, |
| callee_def_id, |
| substs)?; |
| |
| if let InstanceDef::Virtual(..) = instance.def { |
| return None; |
| } |
| |
| return Some(CallSite { |
| callee: instance.def_id(), |
| substs: instance.substs, |
| bb, |
| location: 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); |
| |
| 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.is_local() { |
| if callsite.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 param_env = tcx.param_env(self.source.def_id()); |
| |
| 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 location, target, unwind } | |
| TerminatorKind::DropAndReplace { ref location, target, unwind, .. } => { |
| is_drop = true; |
| work_list.push(target); |
| // If the location doesn't actually need dropping, treat it like |
| // a regular goto. |
| let ty = location.ty(callee_body, tcx).subst(tcx, callsite.substs).ty; |
| if ty.needs_drop(tcx, param_env) { |
| cost += CALL_PENALTY; |
| if let Some(unwind) = unwind { |
| 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), .. } => { |
| 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; |
| } |
| } |
| } |
| TerminatorKind::Assert { .. } => cost += CALL_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.substs); |
| // Cost of the var is the size in machine-words, if we know |
| // it. |
| if let Some(size) = type_size_of(tcx, param_env.clone(), 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, self.source); |
| |
| let mut local_map = IndexVec::with_capacity(callee_body.local_decls.len()); |
| let mut scope_map = IndexVec::with_capacity(callee_body.source_scopes.len()); |
| |
| for mut scope in callee_body.source_scopes.iter().cloned() { |
| if scope.parent_scope.is_none() { |
| scope.parent_scope = Some(callsite.location.scope); |
| scope.span = callee_body.span; |
| } |
| |
| scope.span = callsite.location.span; |
| |
| let idx = caller_body.source_scopes.push(scope); |
| 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 = |
| scope_map[local.source_info.scope]; |
| local.source_info.span = callsite.location.span; |
| |
| let idx = caller_body.local_decls.push(local); |
| local_map.push(idx); |
| } |
| |
| // 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, |
| _ => {} |
| } |
| } |
| |
| match place.base { |
| // Static variables need a borrow because the callee |
| // might modify the same static. |
| PlaceBase::Static(_) => 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_temp(ty, callsite.location.span); |
| |
| let tmp = caller_body.local_decls.push(temp); |
| let tmp = Place::from(tmp); |
| |
| let stmt = Statement { |
| source_info: callsite.location, |
| kind: StatementKind::Assign(box(tmp.clone(), 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); |
| |
| let bb_len = caller_body.basic_blocks().len(); |
| let mut integrator = Integrator { |
| block_idx: bb_len, |
| args: &args, |
| local_map, |
| scope_map, |
| destination: dest, |
| return_block, |
| cleanup_block: cleanup, |
| in_cleanup_block: false, |
| tcx: self.tcx, |
| }; |
| |
| 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.location, |
| 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<Operand<'tcx>>, |
| callsite: &CallSite<'tcx>, |
| caller_body: &mut Body<'tcx>, |
| ) -> Vec<Local> { |
| 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]`. |
| if tcx.is_closure(callsite.callee) { |
| let mut args = args.into_iter(); |
| let self_ = self.create_temp_if_necessary(args.next().unwrap(), callsite, caller_body); |
| let tuple = self.create_temp_if_necessary(args.next().unwrap(), callsite, caller_body); |
| 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.clone(), |
| 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) |
| }); |
| |
| closure_ref_arg.chain(tuple_tmp_args).collect() |
| } else { |
| args.into_iter() |
| .map(|a| self.create_temp_if_necessary(a, callsite, caller_body)) |
| .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>, |
| ) -> 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_temp(ty, callsite.location.span); |
| let arg_tmp = caller_body.local_decls.push(arg_tmp); |
| |
| let stmt = Statement { |
| source_info: callsite.location, |
| kind: StatementKind::Assign(box(Place::from(arg_tmp), arg)), |
| }; |
| caller_body[callsite.bb].statements.push(stmt); |
| arg_tmp |
| } |
| } |
| |
| fn type_size_of<'tcx>( |
| tcx: TyCtxt<'tcx>, |
| param_env: ty::ParamEnv<'tcx>, |
| ty: Ty<'tcx>, |
| ) -> Option<u64> { |
| 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<Local, Local>, |
| scope_map: IndexVec<SourceScope, SourceScope>, |
| destination: Place<'tcx>, |
| return_block: BasicBlock, |
| cleanup_block: Option<BasicBlock>, |
| 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 { |
| match self.destination.as_local() { |
| Some(l) => return l, |
| ref place => bug!("Return place is {:?}, not local", place), |
| } |
| } |
| |
| 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 let Some(RETURN_PLACE) = place.as_local() { |
| // Return pointer; update the place itself |
| *place = self.destination.clone(); |
| } else { |
| self.super_place(place, context, location); |
| } |
| } |
| |
| fn process_projection_elem( |
| &mut self, |
| elem: &PlaceElem<'tcx>, |
| ) -> Option<PlaceElem<'tcx>> { |
| if let PlaceElem::Index(local) = elem { |
| let new_local = self.make_integrate_local(local); |
| |
| if new_local != *local { |
| return Some(PlaceElem::Index(new_local)) |
| } |
| } |
| |
| None |
| } |
| |
| 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_kind(&mut self, |
| kind: &mut TerminatorKind<'tcx>, loc: Location) { |
| self.super_terminator_kind(kind, loc); |
| |
| match *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 { |
| *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 => { |
| *kind = TerminatorKind::Goto { target: self.return_block }; |
| } |
| TerminatorKind::Resume => { |
| if let Some(tgt) = self.cleanup_block { |
| *kind = TerminatorKind::Goto { target: tgt } |
| } |
| } |
| TerminatorKind::Abort => { } |
| TerminatorKind::Unreachable => { } |
| TerminatorKind::FalseEdges { 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") |
| } |
| } |
| |
| fn visit_source_scope(&mut self, scope: &mut SourceScope) { |
| *scope = self.scope_map[*scope]; |
| } |
| } |
