| // Copyright 2014 The Rust Project Developers. See the COPYRIGHT |
| // file at the top-level directory of this distribution and at |
| // http://rust-lang.org/COPYRIGHT. |
| // |
| // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or |
| // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| |
| //! Translation Item Collection |
| //! =========================== |
| //! |
| //! This module is responsible for discovering all items that will contribute to |
| //! to code generation of the crate. The important part here is that it not only |
| //! needs to find syntax-level items (functions, structs, etc) but also all |
| //! their monomorphized instantiations. Every non-generic, non-const function |
| //! maps to one LLVM artifact. Every generic function can produce |
| //! from zero to N artifacts, depending on the sets of type arguments it |
| //! is instantiated with. |
| //! This also applies to generic items from other crates: A generic definition |
| //! in crate X might produce monomorphizations that are compiled into crate Y. |
| //! We also have to collect these here. |
| //! |
| //! The following kinds of "translation items" are handled here: |
| //! |
| //! - Functions |
| //! - Methods |
| //! - Closures |
| //! - Statics |
| //! - Drop glue |
| //! |
| //! The following things also result in LLVM artifacts, but are not collected |
| //! here, since we instantiate them locally on demand when needed in a given |
| //! codegen unit: |
| //! |
| //! - Constants |
| //! - Vtables |
| //! - Object Shims |
| //! |
| //! |
| //! General Algorithm |
| //! ----------------- |
| //! Let's define some terms first: |
| //! |
| //! - A "translation item" is something that results in a function or global in |
| //! the LLVM IR of a codegen unit. Translation items do not stand on their |
| //! own, they can reference other translation items. For example, if function |
| //! `foo()` calls function `bar()` then the translation item for `foo()` |
| //! references the translation item for function `bar()`. In general, the |
| //! definition for translation item A referencing a translation item B is that |
| //! the LLVM artifact produced for A references the LLVM artifact produced |
| //! for B. |
| //! |
| //! - Translation items and the references between them for a directed graph, |
| //! where the translation items are the nodes and references form the edges. |
| //! Let's call this graph the "translation item graph". |
| //! |
| //! - The translation item graph for a program contains all translation items |
| //! that are needed in order to produce the complete LLVM IR of the program. |
| //! |
| //! The purpose of the algorithm implemented in this module is to build the |
| //! translation item graph for the current crate. It runs in two phases: |
| //! |
| //! 1. Discover the roots of the graph by traversing the HIR of the crate. |
| //! 2. Starting from the roots, find neighboring nodes by inspecting the MIR |
| //! representation of the item corresponding to a given node, until no more |
| //! new nodes are found. |
| //! |
| //! ### Discovering roots |
| //! |
| //! The roots of the translation item graph correspond to the non-generic |
| //! syntactic items in the source code. We find them by walking the HIR of the |
| //! crate, and whenever we hit upon a function, method, or static item, we |
| //! create a translation item consisting of the items DefId and, since we only |
| //! consider non-generic items, an empty type-substitution set. |
| //! |
| //! ### Finding neighbor nodes |
| //! Given a translation item node, we can discover neighbors by inspecting its |
| //! MIR. We walk the MIR and any time we hit upon something that signifies a |
| //! reference to another translation item, we have found a neighbor. Since the |
| //! translation item we are currently at is always monomorphic, we also know the |
| //! concrete type arguments of its neighbors, and so all neighbors again will be |
| //! monomorphic. The specific forms a reference to a neighboring node can take |
| //! in MIR are quite diverse. Here is an overview: |
| //! |
| //! #### Calling Functions/Methods |
| //! The most obvious form of one translation item referencing another is a |
| //! function or method call (represented by a CALL terminator in MIR). But |
| //! calls are not the only thing that might introduce a reference between two |
| //! function translation items, and as we will see below, they are just a |
| //! specialized of the form described next, and consequently will don't get any |
| //! special treatment in the algorithm. |
| //! |
| //! #### Taking a reference to a function or method |
| //! A function does not need to actually be called in order to be a neighbor of |
| //! another function. It suffices to just take a reference in order to introduce |
| //! an edge. Consider the following example: |
| //! |
| //! ```rust |
| //! fn print_val<T: Display>(x: T) { |
| //! println!("{}", x); |
| //! } |
| //! |
| //! fn call_fn(f: &Fn(i32), x: i32) { |
| //! f(x); |
| //! } |
| //! |
| //! fn main() { |
| //! let print_i32 = print_val::<i32>; |
| //! call_fn(&print_i32, 0); |
| //! } |
| //! ``` |
| //! The MIR of none of these functions will contain an explicit call to |
| //! `print_val::<i32>`. Nonetheless, in order to translate this program, we need |
| //! an instance of this function. Thus, whenever we encounter a function or |
| //! method in operand position, we treat it as a neighbor of the current |
| //! translation item. Calls are just a special case of that. |
| //! |
| //! #### Closures |
| //! In a way, closures are a simple case. Since every closure object needs to be |
| //! constructed somewhere, we can reliably discover them by observing |
| //! `RValue::Aggregate` expressions with `AggregateKind::Closure`. This is also |
| //! true for closures inlined from other crates. |
| //! |
| //! #### Drop glue |
| //! Drop glue translation items are introduced by MIR drop-statements. The |
| //! generated translation item will again have drop-glue item neighbors if the |
| //! type to be dropped contains nested values that also need to be dropped. It |
| //! might also have a function item neighbor for the explicit `Drop::drop` |
| //! implementation of its type. |
| //! |
| //! #### Unsizing Casts |
| //! A subtle way of introducing neighbor edges is by casting to a trait object. |
| //! Since the resulting fat-pointer contains a reference to a vtable, we need to |
| //! instantiate all object-save methods of the trait, as we need to store |
| //! pointers to these functions even if they never get called anywhere. This can |
| //! be seen as a special case of taking a function reference. |
| //! |
| //! #### Boxes |
| //! Since `Box` expression have special compiler support, no explicit calls to |
| //! `exchange_malloc()` and `exchange_free()` may show up in MIR, even if the |
| //! compiler will generate them. We have to observe `Rvalue::Box` expressions |
| //! and Box-typed drop-statements for that purpose. |
| //! |
| //! |
| //! Interaction with Cross-Crate Inlining |
| //! ------------------------------------- |
| //! The binary of a crate will not only contain machine code for the items |
| //! defined in the source code of that crate. It will also contain monomorphic |
| //! instantiations of any extern generic functions and of functions marked with |
| //! #[inline]. |
| //! The collection algorithm handles this more or less transparently. If it is |
| //! about to create a translation item for something with an external `DefId`, |
| //! it will take a look if the MIR for that item is available, and if so just |
| //! proceed normally. If the MIR is not available, it assumes that that item is |
| //! just linked to and no node is created; which is exactly what we want, since |
| //! no machine code should be generated in the current crate for such an item. |
| //! |
| //! Eager and Lazy Collection Mode |
| //! ------------------------------ |
| //! Translation item collection can be performed in one of two modes: |
| //! |
| //! - Lazy mode means that items will only be instantiated when actually |
| //! referenced. The goal is to produce the least amount of machine code |
| //! possible. |
| //! |
| //! - Eager mode is meant to be used in conjunction with incremental compilation |
| //! where a stable set of translation items is more important than a minimal |
| //! one. Thus, eager mode will instantiate drop-glue for every drop-able type |
| //! in the crate, even of no drop call for that type exists (yet). It will |
| //! also instantiate default implementations of trait methods, something that |
| //! otherwise is only done on demand. |
| //! |
| //! |
| //! Open Issues |
| //! ----------- |
| //! Some things are not yet fully implemented in the current version of this |
| //! module. |
| //! |
| //! ### Initializers of Constants and Statics |
| //! Since no MIR is constructed yet for initializer expressions of constants and |
| //! statics we cannot inspect these properly. |
| //! |
| //! ### Const Fns |
| //! Ideally, no translation item should be generated for const fns unless there |
| //! is a call to them that cannot be evaluated at compile time. At the moment |
| //! this is not implemented however: a translation item will be produced |
| //! regardless of whether it is actually needed or not. |
| |
| use rustc::hir; |
| use rustc::hir::intravisit as hir_visit; |
| |
| use rustc::hir::map as hir_map; |
| use rustc::hir::def_id::DefId; |
| use rustc::middle::lang_items::{ExchangeFreeFnLangItem, ExchangeMallocFnLangItem}; |
| use rustc::traits; |
| use rustc::ty::subst::{self, Substs, Subst}; |
| use rustc::ty::{self, TypeFoldable, TyCtxt}; |
| use rustc::ty::adjustment::CustomCoerceUnsized; |
| use rustc::mir::repr as mir; |
| use rustc::mir::visit as mir_visit; |
| use rustc::mir::visit::Visitor as MirVisitor; |
| |
| use syntax::abi::Abi; |
| use errors; |
| use syntax_pos::DUMMY_SP; |
| use syntax::ast::NodeId; |
| use base::custom_coerce_unsize_info; |
| use context::SharedCrateContext; |
| use common::{fulfill_obligation, normalize_and_test_predicates, type_is_sized}; |
| use glue::{self, DropGlueKind}; |
| use meth; |
| use monomorphize::{self, Instance}; |
| use util::nodemap::{FnvHashSet, FnvHashMap, DefIdMap}; |
| |
| use trans_item::{TransItem, type_to_string, def_id_to_string}; |
| |
| #[derive(PartialEq, Eq, Hash, Clone, Copy, Debug)] |
| pub enum TransItemCollectionMode { |
| Eager, |
| Lazy |
| } |
| |
| /// Maps every translation item to all translation items it references in its |
| /// body. |
| pub struct InliningMap<'tcx> { |
| // Maps a source translation item to a range of target translation items |
| // that are potentially inlined by LLVM into the source. |
| // The two numbers in the tuple are the start (inclusive) and |
| // end index (exclusive) within the `targets` vecs. |
| index: FnvHashMap<TransItem<'tcx>, (usize, usize)>, |
| targets: Vec<TransItem<'tcx>>, |
| } |
| |
| impl<'tcx> InliningMap<'tcx> { |
| |
| fn new() -> InliningMap<'tcx> { |
| InliningMap { |
| index: FnvHashMap(), |
| targets: Vec::new(), |
| } |
| } |
| |
| fn record_inlining_canditates<I>(&mut self, |
| source: TransItem<'tcx>, |
| targets: I) |
| where I: Iterator<Item=TransItem<'tcx>> |
| { |
| assert!(!self.index.contains_key(&source)); |
| |
| let start_index = self.targets.len(); |
| self.targets.extend(targets); |
| let end_index = self.targets.len(); |
| self.index.insert(source, (start_index, end_index)); |
| } |
| |
| // Internally iterate over all items referenced by `source` which will be |
| // made available for inlining. |
| pub fn with_inlining_candidates<F>(&self, source: TransItem<'tcx>, mut f: F) |
| where F: FnMut(TransItem<'tcx>) { |
| if let Some(&(start_index, end_index)) = self.index.get(&source) |
| { |
| for candidate in &self.targets[start_index .. end_index] { |
| f(*candidate) |
| } |
| } |
| } |
| } |
| |
| pub fn collect_crate_translation_items<'a, 'tcx>(scx: &SharedCrateContext<'a, 'tcx>, |
| mode: TransItemCollectionMode) |
| -> (FnvHashSet<TransItem<'tcx>>, |
| InliningMap<'tcx>) { |
| // We are not tracking dependencies of this pass as it has to be re-executed |
| // every time no matter what. |
| scx.tcx().dep_graph.with_ignore(|| { |
| let roots = collect_roots(scx, mode); |
| |
| debug!("Building translation item graph, beginning at roots"); |
| let mut visited = FnvHashSet(); |
| let mut recursion_depths = DefIdMap(); |
| let mut inlining_map = InliningMap::new(); |
| |
| for root in roots { |
| collect_items_rec(scx, |
| root, |
| &mut visited, |
| &mut recursion_depths, |
| &mut inlining_map); |
| } |
| |
| (visited, inlining_map) |
| }) |
| } |
| |
| // Find all non-generic items by walking the HIR. These items serve as roots to |
| // start monomorphizing from. |
| fn collect_roots<'a, 'tcx>(scx: &SharedCrateContext<'a, 'tcx>, |
| mode: TransItemCollectionMode) |
| -> Vec<TransItem<'tcx>> { |
| debug!("Collecting roots"); |
| let mut roots = Vec::new(); |
| |
| { |
| let mut visitor = RootCollector { |
| scx: scx, |
| mode: mode, |
| output: &mut roots, |
| enclosing_item: None, |
| }; |
| |
| scx.tcx().map.krate().visit_all_items(&mut visitor); |
| } |
| |
| roots |
| } |
| |
| // Collect all monomorphized translation items reachable from `starting_point` |
| fn collect_items_rec<'a, 'tcx: 'a>(scx: &SharedCrateContext<'a, 'tcx>, |
| starting_point: TransItem<'tcx>, |
| visited: &mut FnvHashSet<TransItem<'tcx>>, |
| recursion_depths: &mut DefIdMap<usize>, |
| inlining_map: &mut InliningMap<'tcx>) { |
| if !visited.insert(starting_point.clone()) { |
| // We've been here already, no need to search again. |
| return; |
| } |
| debug!("BEGIN collect_items_rec({})", starting_point.to_string(scx.tcx())); |
| |
| let mut neighbors = Vec::new(); |
| let recursion_depth_reset; |
| |
| match starting_point { |
| TransItem::DropGlue(t) => { |
| find_drop_glue_neighbors(scx, t, &mut neighbors); |
| recursion_depth_reset = None; |
| } |
| TransItem::Static(node_id) => { |
| let def_id = scx.tcx().map.local_def_id(node_id); |
| let ty = scx.tcx().lookup_item_type(def_id).ty; |
| let ty = glue::get_drop_glue_type(scx.tcx(), ty); |
| neighbors.push(TransItem::DropGlue(DropGlueKind::Ty(ty))); |
| |
| recursion_depth_reset = None; |
| |
| // Scan the MIR in order to find function calls, closures, and |
| // drop-glue |
| let mir = errors::expect(scx.sess().diagnostic(), scx.get_mir(def_id), |
| || format!("Could not find MIR for static: {:?}", def_id)); |
| |
| let empty_substs = scx.empty_substs_for_def_id(def_id); |
| let visitor = MirNeighborCollector { |
| scx: scx, |
| mir: &mir, |
| output: &mut neighbors, |
| param_substs: empty_substs |
| }; |
| |
| visit_mir_and_promoted(visitor, &mir); |
| } |
| TransItem::Fn(instance) => { |
| // Keep track of the monomorphization recursion depth |
| recursion_depth_reset = Some(check_recursion_limit(scx.tcx(), |
| instance, |
| recursion_depths)); |
| |
| // Scan the MIR in order to find function calls, closures, and |
| // drop-glue |
| let mir = errors::expect(scx.sess().diagnostic(), scx.get_mir(instance.def), |
| || format!("Could not find MIR for function: {}", instance)); |
| |
| let visitor = MirNeighborCollector { |
| scx: scx, |
| mir: &mir, |
| output: &mut neighbors, |
| param_substs: instance.substs |
| }; |
| |
| visit_mir_and_promoted(visitor, &mir); |
| } |
| } |
| |
| record_inlining_canditates(scx.tcx(), starting_point, &neighbors[..], inlining_map); |
| |
| for neighbour in neighbors { |
| collect_items_rec(scx, neighbour, visited, recursion_depths, inlining_map); |
| } |
| |
| if let Some((def_id, depth)) = recursion_depth_reset { |
| recursion_depths.insert(def_id, depth); |
| } |
| |
| debug!("END collect_items_rec({})", starting_point.to_string(scx.tcx())); |
| } |
| |
| fn record_inlining_canditates<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, |
| caller: TransItem<'tcx>, |
| callees: &[TransItem<'tcx>], |
| inlining_map: &mut InliningMap<'tcx>) { |
| let is_inlining_candidate = |trans_item: &TransItem<'tcx>| { |
| trans_item.is_from_extern_crate() || trans_item.requests_inline(tcx) |
| }; |
| |
| let inlining_candidates = callees.into_iter() |
| .map(|x| *x) |
| .filter(is_inlining_candidate); |
| |
| inlining_map.record_inlining_canditates(caller, inlining_candidates); |
| } |
| |
| fn check_recursion_limit<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, |
| instance: Instance<'tcx>, |
| recursion_depths: &mut DefIdMap<usize>) |
| -> (DefId, usize) { |
| let recursion_depth = recursion_depths.get(&instance.def) |
| .map(|x| *x) |
| .unwrap_or(0); |
| debug!(" => recursion depth={}", recursion_depth); |
| |
| // Code that needs to instantiate the same function recursively |
| // more than the recursion limit is assumed to be causing an |
| // infinite expansion. |
| if recursion_depth > tcx.sess.recursion_limit.get() { |
| let error = format!("reached the recursion limit while instantiating `{}`", |
| instance); |
| if let Some(node_id) = tcx.map.as_local_node_id(instance.def) { |
| tcx.sess.span_fatal(tcx.map.span(node_id), &error); |
| } else { |
| tcx.sess.fatal(&error); |
| } |
| } |
| |
| recursion_depths.insert(instance.def, recursion_depth + 1); |
| |
| (instance.def, recursion_depth) |
| } |
| |
| struct MirNeighborCollector<'a, 'tcx: 'a> { |
| scx: &'a SharedCrateContext<'a, 'tcx>, |
| mir: &'a mir::Mir<'tcx>, |
| output: &'a mut Vec<TransItem<'tcx>>, |
| param_substs: &'tcx Substs<'tcx> |
| } |
| |
| impl<'a, 'tcx> MirVisitor<'tcx> for MirNeighborCollector<'a, 'tcx> { |
| |
| fn visit_rvalue(&mut self, rvalue: &mir::Rvalue<'tcx>) { |
| debug!("visiting rvalue {:?}", *rvalue); |
| |
| match *rvalue { |
| mir::Rvalue::Aggregate(mir::AggregateKind::Closure(def_id, |
| ref substs), _) => { |
| let mir = errors::expect(self.scx.sess().diagnostic(), |
| self.scx.get_mir(def_id), |
| || { |
| format!("Could not find MIR for closure: {:?}", def_id) |
| }); |
| |
| let concrete_substs = monomorphize::apply_param_substs(self.scx.tcx(), |
| self.param_substs, |
| &substs.func_substs); |
| let concrete_substs = self.scx.tcx().erase_regions(&concrete_substs); |
| |
| let visitor = MirNeighborCollector { |
| scx: self.scx, |
| mir: &mir, |
| output: self.output, |
| param_substs: concrete_substs |
| }; |
| |
| visit_mir_and_promoted(visitor, &mir); |
| } |
| // When doing an cast from a regular pointer to a fat pointer, we |
| // have to instantiate all methods of the trait being cast to, so we |
| // can build the appropriate vtable. |
| mir::Rvalue::Cast(mir::CastKind::Unsize, ref operand, target_ty) => { |
| let target_ty = monomorphize::apply_param_substs(self.scx.tcx(), |
| self.param_substs, |
| &target_ty); |
| let source_ty = self.mir.operand_ty(self.scx.tcx(), operand); |
| let source_ty = monomorphize::apply_param_substs(self.scx.tcx(), |
| self.param_substs, |
| &source_ty); |
| let (source_ty, target_ty) = find_vtable_types_for_unsizing(self.scx, |
| source_ty, |
| target_ty); |
| // This could also be a different Unsize instruction, like |
| // from a fixed sized array to a slice. But we are only |
| // interested in things that produce a vtable. |
| if target_ty.is_trait() && !source_ty.is_trait() { |
| create_trans_items_for_vtable_methods(self.scx, |
| target_ty, |
| source_ty, |
| self.output); |
| } |
| } |
| mir::Rvalue::Box(_) => { |
| let exchange_malloc_fn_def_id = |
| self.scx |
| .tcx() |
| .lang_items |
| .require(ExchangeMallocFnLangItem) |
| .unwrap_or_else(|e| self.scx.sess().fatal(&e)); |
| |
| assert!(can_have_local_instance(self.scx.tcx(), exchange_malloc_fn_def_id)); |
| let empty_substs = self.scx.empty_substs_for_def_id(exchange_malloc_fn_def_id); |
| let exchange_malloc_fn_trans_item = |
| create_fn_trans_item(self.scx.tcx(), |
| exchange_malloc_fn_def_id, |
| empty_substs, |
| self.param_substs); |
| |
| self.output.push(exchange_malloc_fn_trans_item); |
| } |
| _ => { /* not interesting */ } |
| } |
| |
| self.super_rvalue(rvalue); |
| } |
| |
| fn visit_lvalue(&mut self, |
| lvalue: &mir::Lvalue<'tcx>, |
| context: mir_visit::LvalueContext) { |
| debug!("visiting lvalue {:?}", *lvalue); |
| |
| if let mir_visit::LvalueContext::Drop = context { |
| let ty = self.mir.lvalue_ty(self.scx.tcx(), lvalue) |
| .to_ty(self.scx.tcx()); |
| |
| let ty = monomorphize::apply_param_substs(self.scx.tcx(), |
| self.param_substs, |
| &ty); |
| assert!(ty.is_normalized_for_trans()); |
| let ty = glue::get_drop_glue_type(self.scx.tcx(), ty); |
| self.output.push(TransItem::DropGlue(DropGlueKind::Ty(ty))); |
| } |
| |
| self.super_lvalue(lvalue, context); |
| } |
| |
| fn visit_operand(&mut self, operand: &mir::Operand<'tcx>) { |
| debug!("visiting operand {:?}", *operand); |
| |
| let callee = match *operand { |
| mir::Operand::Constant(mir::Constant { ty: &ty::TyS { |
| sty: ty::TyFnDef(def_id, substs, _), .. |
| }, .. }) => Some((def_id, substs)), |
| _ => None |
| }; |
| |
| if let Some((callee_def_id, callee_substs)) = callee { |
| debug!(" => operand is callable"); |
| |
| // `callee_def_id` might refer to a trait method instead of a |
| // concrete implementation, so we have to find the actual |
| // implementation. For example, the call might look like |
| // |
| // std::cmp::partial_cmp(0i32, 1i32) |
| // |
| // Calling do_static_dispatch() here will map the def_id of |
| // `std::cmp::partial_cmp` to the def_id of `i32::partial_cmp<i32>` |
| let dispatched = do_static_dispatch(self.scx, |
| callee_def_id, |
| callee_substs, |
| self.param_substs); |
| |
| if let Some((callee_def_id, callee_substs)) = dispatched { |
| // if we have a concrete impl (which we might not have |
| // in the case of something compiler generated like an |
| // object shim or a closure that is handled differently), |
| // we check if the callee is something that will actually |
| // result in a translation item ... |
| if can_result_in_trans_item(self.scx.tcx(), callee_def_id) { |
| // ... and create one if it does. |
| let trans_item = create_fn_trans_item(self.scx.tcx(), |
| callee_def_id, |
| callee_substs, |
| self.param_substs); |
| self.output.push(trans_item); |
| } |
| } |
| } |
| |
| self.super_operand(operand); |
| |
| fn can_result_in_trans_item<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, |
| def_id: DefId) |
| -> bool { |
| if !match tcx.lookup_item_type(def_id).ty.sty { |
| ty::TyFnDef(def_id, _, _) => { |
| // Some constructors also have type TyFnDef but they are |
| // always instantiated inline and don't result in |
| // translation item. Same for FFI functions. |
| match tcx.map.get_if_local(def_id) { |
| Some(hir_map::NodeVariant(_)) | |
| Some(hir_map::NodeStructCtor(_)) | |
| Some(hir_map::NodeForeignItem(_)) => false, |
| Some(_) => true, |
| None => { |
| tcx.sess.cstore.variant_kind(def_id).is_none() |
| } |
| } |
| } |
| ty::TyClosure(..) => true, |
| _ => false |
| } { |
| return false; |
| } |
| |
| can_have_local_instance(tcx, def_id) |
| } |
| } |
| |
| // This takes care of the "drop_in_place" intrinsic for which we otherwise |
| // we would not register drop-glues. |
| fn visit_terminator_kind(&mut self, |
| block: mir::BasicBlock, |
| kind: &mir::TerminatorKind<'tcx>) { |
| let tcx = self.scx.tcx(); |
| match *kind { |
| mir::TerminatorKind::Call { |
| func: mir::Operand::Constant(ref constant), |
| ref args, |
| .. |
| } => { |
| match constant.ty.sty { |
| ty::TyFnDef(def_id, _, bare_fn_ty) |
| if is_drop_in_place_intrinsic(tcx, def_id, bare_fn_ty) => { |
| let operand_ty = self.mir.operand_ty(tcx, &args[0]); |
| if let ty::TyRawPtr(mt) = operand_ty.sty { |
| let operand_ty = monomorphize::apply_param_substs(tcx, |
| self.param_substs, |
| &mt.ty); |
| let ty = glue::get_drop_glue_type(tcx, operand_ty); |
| self.output.push(TransItem::DropGlue(DropGlueKind::Ty(ty))); |
| } else { |
| bug!("Has the drop_in_place() intrinsic's signature changed?") |
| } |
| } |
| _ => { /* Nothing to do. */ } |
| } |
| } |
| _ => { /* Nothing to do. */ } |
| } |
| |
| self.super_terminator_kind(block, kind); |
| |
| fn is_drop_in_place_intrinsic<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, |
| def_id: DefId, |
| bare_fn_ty: &ty::BareFnTy<'tcx>) |
| -> bool { |
| (bare_fn_ty.abi == Abi::RustIntrinsic || |
| bare_fn_ty.abi == Abi::PlatformIntrinsic) && |
| tcx.item_name(def_id).as_str() == "drop_in_place" |
| } |
| } |
| } |
| |
| fn can_have_local_instance<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, |
| def_id: DefId) |
| -> bool { |
| // Take a look if we have the definition available. If not, we |
| // will not emit code for this item in the local crate, and thus |
| // don't create a translation item for it. |
| def_id.is_local() || tcx.sess.cstore.is_item_mir_available(def_id) |
| } |
| |
| fn find_drop_glue_neighbors<'a, 'tcx>(scx: &SharedCrateContext<'a, 'tcx>, |
| dg: DropGlueKind<'tcx>, |
| output: &mut Vec<TransItem<'tcx>>) { |
| let ty = match dg { |
| DropGlueKind::Ty(ty) => ty, |
| DropGlueKind::TyContents(_) => { |
| // We already collected the neighbors of this item via the |
| // DropGlueKind::Ty variant. |
| return |
| } |
| }; |
| |
| debug!("find_drop_glue_neighbors: {}", type_to_string(scx.tcx(), ty)); |
| |
| // Make sure the exchange_free_fn() lang-item gets translated if |
| // there is a boxed value. |
| if let ty::TyBox(_) = ty.sty { |
| let exchange_free_fn_def_id = scx.tcx() |
| .lang_items |
| .require(ExchangeFreeFnLangItem) |
| .unwrap_or_else(|e| scx.sess().fatal(&e)); |
| |
| assert!(can_have_local_instance(scx.tcx(), exchange_free_fn_def_id)); |
| let fn_substs = scx.empty_substs_for_def_id(exchange_free_fn_def_id); |
| let exchange_free_fn_trans_item = |
| create_fn_trans_item(scx.tcx(), |
| exchange_free_fn_def_id, |
| fn_substs, |
| scx.tcx().mk_substs(Substs::empty())); |
| |
| output.push(exchange_free_fn_trans_item); |
| } |
| |
| // If the type implements Drop, also add a translation item for the |
| // monomorphized Drop::drop() implementation. |
| let destructor_did = match ty.sty { |
| ty::TyStruct(def, _) | |
| ty::TyEnum(def, _) => def.destructor(), |
| _ => None |
| }; |
| |
| if let Some(destructor_did) = destructor_did { |
| use rustc::ty::ToPolyTraitRef; |
| |
| let drop_trait_def_id = scx.tcx() |
| .lang_items |
| .drop_trait() |
| .unwrap(); |
| |
| let self_type_substs = scx.tcx().mk_substs( |
| Substs::empty().with_self_ty(ty)); |
| |
| let trait_ref = ty::TraitRef { |
| def_id: drop_trait_def_id, |
| substs: self_type_substs, |
| }.to_poly_trait_ref(); |
| |
| let substs = match fulfill_obligation(scx, DUMMY_SP, trait_ref) { |
| traits::VtableImpl(data) => data.substs, |
| _ => bug!() |
| }; |
| |
| if can_have_local_instance(scx.tcx(), destructor_did) { |
| let trans_item = create_fn_trans_item(scx.tcx(), |
| destructor_did, |
| substs, |
| scx.tcx().mk_substs(Substs::empty())); |
| output.push(trans_item); |
| } |
| |
| // This type has a Drop implementation, we'll need the contents-only |
| // version of the glue too. |
| output.push(TransItem::DropGlue(DropGlueKind::TyContents(ty))); |
| } |
| |
| // Finally add the types of nested values |
| match ty.sty { |
| ty::TyBool | |
| ty::TyChar | |
| ty::TyInt(_) | |
| ty::TyUint(_) | |
| ty::TyStr | |
| ty::TyFloat(_) | |
| ty::TyRawPtr(_) | |
| ty::TyRef(..) | |
| ty::TyFnDef(..) | |
| ty::TyFnPtr(_) | |
| ty::TyTrait(_) => { |
| /* nothing to do */ |
| } |
| ty::TyStruct(ref adt_def, substs) | |
| ty::TyEnum(ref adt_def, substs) => { |
| for field in adt_def.all_fields() { |
| let field_type = monomorphize::apply_param_substs(scx.tcx(), |
| substs, |
| &field.unsubst_ty()); |
| let field_type = glue::get_drop_glue_type(scx.tcx(), field_type); |
| |
| if glue::type_needs_drop(scx.tcx(), field_type) { |
| output.push(TransItem::DropGlue(DropGlueKind::Ty(field_type))); |
| } |
| } |
| } |
| ty::TyClosure(_, substs) => { |
| for upvar_ty in substs.upvar_tys { |
| let upvar_ty = glue::get_drop_glue_type(scx.tcx(), upvar_ty); |
| if glue::type_needs_drop(scx.tcx(), upvar_ty) { |
| output.push(TransItem::DropGlue(DropGlueKind::Ty(upvar_ty))); |
| } |
| } |
| } |
| ty::TyBox(inner_type) | |
| ty::TySlice(inner_type) | |
| ty::TyArray(inner_type, _) => { |
| let inner_type = glue::get_drop_glue_type(scx.tcx(), inner_type); |
| if glue::type_needs_drop(scx.tcx(), inner_type) { |
| output.push(TransItem::DropGlue(DropGlueKind::Ty(inner_type))); |
| } |
| } |
| ty::TyTuple(args) => { |
| for arg in args { |
| let arg = glue::get_drop_glue_type(scx.tcx(), arg); |
| if glue::type_needs_drop(scx.tcx(), arg) { |
| output.push(TransItem::DropGlue(DropGlueKind::Ty(arg))); |
| } |
| } |
| } |
| ty::TyProjection(_) | |
| ty::TyParam(_) | |
| ty::TyInfer(_) | |
| ty::TyError => { |
| bug!("encountered unexpected type"); |
| } |
| } |
| |
| |
| } |
| |
| fn do_static_dispatch<'a, 'tcx>(scx: &SharedCrateContext<'a, 'tcx>, |
| fn_def_id: DefId, |
| fn_substs: &'tcx Substs<'tcx>, |
| param_substs: &'tcx Substs<'tcx>) |
| -> Option<(DefId, &'tcx Substs<'tcx>)> { |
| debug!("do_static_dispatch(fn_def_id={}, fn_substs={:?}, param_substs={:?})", |
| def_id_to_string(scx.tcx(), fn_def_id), |
| fn_substs, |
| param_substs); |
| |
| let is_trait_method = scx.tcx().trait_of_item(fn_def_id).is_some(); |
| |
| if is_trait_method { |
| match scx.tcx().impl_or_trait_item(fn_def_id) { |
| ty::MethodTraitItem(ref method) => { |
| match method.container { |
| ty::TraitContainer(trait_def_id) => { |
| debug!(" => trait method, attempting to find impl"); |
| do_static_trait_method_dispatch(scx, |
| method, |
| trait_def_id, |
| fn_substs, |
| param_substs) |
| } |
| ty::ImplContainer(_) => { |
| // This is already a concrete implementation |
| debug!(" => impl method"); |
| Some((fn_def_id, fn_substs)) |
| } |
| } |
| } |
| _ => bug!() |
| } |
| } else { |
| debug!(" => regular function"); |
| // The function is not part of an impl or trait, no dispatching |
| // to be done |
| Some((fn_def_id, fn_substs)) |
| } |
| } |
| |
| // Given a trait-method and substitution information, find out the actual |
| // implementation of the trait method. |
| fn do_static_trait_method_dispatch<'a, 'tcx>(scx: &SharedCrateContext<'a, 'tcx>, |
| trait_method: &ty::Method, |
| trait_id: DefId, |
| callee_substs: &'tcx Substs<'tcx>, |
| param_substs: &'tcx Substs<'tcx>) |
| -> Option<(DefId, &'tcx Substs<'tcx>)> { |
| let tcx = scx.tcx(); |
| debug!("do_static_trait_method_dispatch(trait_method={}, \ |
| trait_id={}, \ |
| callee_substs={:?}, \ |
| param_substs={:?}", |
| def_id_to_string(scx.tcx(), trait_method.def_id), |
| def_id_to_string(scx.tcx(), trait_id), |
| callee_substs, |
| param_substs); |
| |
| let rcvr_substs = monomorphize::apply_param_substs(tcx, |
| param_substs, |
| &callee_substs); |
| |
| let trait_ref = ty::Binder(rcvr_substs.to_trait_ref(tcx, trait_id)); |
| let trait_ref = tcx.normalize_associated_type(&trait_ref); |
| let vtbl = fulfill_obligation(scx, DUMMY_SP, trait_ref); |
| |
| // Now that we know which impl is being used, we can dispatch to |
| // the actual function: |
| match vtbl { |
| traits::VtableImpl(traits::VtableImplData { |
| impl_def_id: impl_did, |
| substs: impl_substs, |
| nested: _ }) => |
| { |
| let callee_substs = impl_substs.with_method_from(&rcvr_substs); |
| let impl_method = meth::get_impl_method(tcx, |
| impl_did, |
| tcx.mk_substs(callee_substs), |
| trait_method.name); |
| Some((impl_method.method.def_id, &impl_method.substs)) |
| } |
| // If we have a closure or a function pointer, we will also encounter |
| // the concrete closure/function somewhere else (during closure or fn |
| // pointer construction). That's where we track those things. |
| traits::VtableClosure(..) | |
| traits::VtableFnPointer(..) | |
| traits::VtableObject(..) => { |
| None |
| } |
| _ => { |
| bug!("static call to invalid vtable: {:?}", vtbl) |
| } |
| } |
| } |
| |
| /// For given pair of source and target type that occur in an unsizing coercion, |
| /// this function finds the pair of types that determines the vtable linking |
| /// them. |
| /// |
| /// For example, the source type might be `&SomeStruct` and the target type\ |
| /// might be `&SomeTrait` in a cast like: |
| /// |
| /// let src: &SomeStruct = ...; |
| /// let target = src as &SomeTrait; |
| /// |
| /// Then the output of this function would be (SomeStruct, SomeTrait) since for |
| /// constructing the `target` fat-pointer we need the vtable for that pair. |
| /// |
| /// Things can get more complicated though because there's also the case where |
| /// the unsized type occurs as a field: |
| /// |
| /// ```rust |
| /// struct ComplexStruct<T: ?Sized> { |
| /// a: u32, |
| /// b: f64, |
| /// c: T |
| /// } |
| /// ``` |
| /// |
| /// In this case, if `T` is sized, `&ComplexStruct<T>` is a thin pointer. If `T` |
| /// is unsized, `&SomeStruct` is a fat pointer, and the vtable it points to is |
| /// for the pair of `T` (which is a trait) and the concrete type that `T` was |
| /// originally coerced from: |
| /// |
| /// let src: &ComplexStruct<SomeStruct> = ...; |
| /// let target = src as &ComplexStruct<SomeTrait>; |
| /// |
| /// Again, we want this `find_vtable_types_for_unsizing()` to provide the pair |
| /// `(SomeStruct, SomeTrait)`. |
| /// |
| /// Finally, there is also the case of custom unsizing coercions, e.g. for |
| /// smart pointers such as `Rc` and `Arc`. |
| fn find_vtable_types_for_unsizing<'a, 'tcx>(scx: &SharedCrateContext<'a, 'tcx>, |
| source_ty: ty::Ty<'tcx>, |
| target_ty: ty::Ty<'tcx>) |
| -> (ty::Ty<'tcx>, ty::Ty<'tcx>) { |
| match (&source_ty.sty, &target_ty.sty) { |
| (&ty::TyBox(a), &ty::TyBox(b)) | |
| (&ty::TyRef(_, ty::TypeAndMut { ty: a, .. }), |
| &ty::TyRef(_, ty::TypeAndMut { ty: b, .. })) | |
| (&ty::TyRef(_, ty::TypeAndMut { ty: a, .. }), |
| &ty::TyRawPtr(ty::TypeAndMut { ty: b, .. })) | |
| (&ty::TyRawPtr(ty::TypeAndMut { ty: a, .. }), |
| &ty::TyRawPtr(ty::TypeAndMut { ty: b, .. })) => { |
| let (inner_source, inner_target) = (a, b); |
| |
| if !type_is_sized(scx.tcx(), inner_source) { |
| (inner_source, inner_target) |
| } else { |
| scx.tcx().struct_lockstep_tails(inner_source, inner_target) |
| } |
| } |
| |
| (&ty::TyStruct(source_adt_def, source_substs), |
| &ty::TyStruct(target_adt_def, target_substs)) => { |
| assert_eq!(source_adt_def, target_adt_def); |
| |
| let kind = custom_coerce_unsize_info(scx, source_ty, target_ty); |
| |
| let coerce_index = match kind { |
| CustomCoerceUnsized::Struct(i) => i |
| }; |
| |
| let source_fields = &source_adt_def.struct_variant().fields; |
| let target_fields = &target_adt_def.struct_variant().fields; |
| |
| assert!(coerce_index < source_fields.len() && |
| source_fields.len() == target_fields.len()); |
| |
| find_vtable_types_for_unsizing(scx, |
| source_fields[coerce_index].ty(scx.tcx(), |
| source_substs), |
| target_fields[coerce_index].ty(scx.tcx(), |
| target_substs)) |
| } |
| _ => bug!("find_vtable_types_for_unsizing: invalid coercion {:?} -> {:?}", |
| source_ty, |
| target_ty) |
| } |
| } |
| |
| fn create_fn_trans_item<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, |
| def_id: DefId, |
| fn_substs: &'tcx Substs<'tcx>, |
| param_substs: &'tcx Substs<'tcx>) |
| -> TransItem<'tcx> { |
| debug!("create_fn_trans_item(def_id={}, fn_substs={:?}, param_substs={:?})", |
| def_id_to_string(tcx, def_id), |
| fn_substs, |
| param_substs); |
| |
| // We only get here, if fn_def_id either designates a local item or |
| // an inlineable external item. Non-inlineable external items are |
| // ignored because we don't want to generate any code for them. |
| let concrete_substs = monomorphize::apply_param_substs(tcx, |
| param_substs, |
| &fn_substs); |
| assert!(concrete_substs.is_normalized_for_trans()); |
| TransItem::Fn(Instance::new(def_id, concrete_substs)) |
| } |
| |
| /// Creates a `TransItem` for each method that is referenced by the vtable for |
| /// the given trait/impl pair. |
| fn create_trans_items_for_vtable_methods<'a, 'tcx>(scx: &SharedCrateContext<'a, 'tcx>, |
| trait_ty: ty::Ty<'tcx>, |
| impl_ty: ty::Ty<'tcx>, |
| output: &mut Vec<TransItem<'tcx>>) { |
| assert!(!trait_ty.needs_subst() && !impl_ty.needs_subst()); |
| |
| if let ty::TyTrait(ref trait_ty) = trait_ty.sty { |
| let poly_trait_ref = trait_ty.principal_trait_ref_with_self_ty(scx.tcx(), |
| impl_ty); |
| |
| // Walk all methods of the trait, including those of its supertraits |
| for trait_ref in traits::supertraits(scx.tcx(), poly_trait_ref) { |
| let vtable = fulfill_obligation(scx, DUMMY_SP, trait_ref); |
| match vtable { |
| traits::VtableImpl( |
| traits::VtableImplData { |
| impl_def_id, |
| substs, |
| nested: _ }) => { |
| let items = meth::get_vtable_methods(scx.tcx(), impl_def_id, substs) |
| .into_iter() |
| // filter out None values |
| .filter_map(|opt_impl_method| opt_impl_method) |
| // create translation items |
| .filter_map(|impl_method| { |
| if can_have_local_instance(scx.tcx(), impl_method.method.def_id) { |
| Some(create_fn_trans_item(scx.tcx(), |
| impl_method.method.def_id, |
| impl_method.substs, |
| scx.tcx().mk_substs(Substs::empty()))) |
| } else { |
| None |
| } |
| }); |
| |
| output.extend(items); |
| |
| // Also add the destructor |
| let dg_type = glue::get_drop_glue_type(scx.tcx(), |
| trait_ref.self_ty()); |
| output.push(TransItem::DropGlue(DropGlueKind::Ty(dg_type))); |
| } |
| _ => { /* */ } |
| } |
| } |
| } |
| } |
| |
| //=----------------------------------------------------------------------------- |
| // Root Collection |
| //=----------------------------------------------------------------------------- |
| |
| struct RootCollector<'b, 'a: 'b, 'tcx: 'a + 'b> { |
| scx: &'b SharedCrateContext<'a, 'tcx>, |
| mode: TransItemCollectionMode, |
| output: &'b mut Vec<TransItem<'tcx>>, |
| enclosing_item: Option<&'tcx hir::Item>, |
| } |
| |
| impl<'b, 'a, 'v> hir_visit::Visitor<'v> for RootCollector<'b, 'a, 'v> { |
| fn visit_item(&mut self, item: &'v hir::Item) { |
| let old_enclosing_item = self.enclosing_item; |
| self.enclosing_item = Some(item); |
| |
| match item.node { |
| hir::ItemExternCrate(..) | |
| hir::ItemUse(..) | |
| hir::ItemForeignMod(..) | |
| hir::ItemTy(..) | |
| hir::ItemDefaultImpl(..) | |
| hir::ItemTrait(..) | |
| hir::ItemMod(..) => { |
| // Nothing to do, just keep recursing... |
| } |
| |
| hir::ItemImpl(..) => { |
| if self.mode == TransItemCollectionMode::Eager { |
| create_trans_items_for_default_impls(self.scx.tcx(), |
| item, |
| self.output); |
| } |
| } |
| |
| hir::ItemEnum(_, ref generics) | |
| hir::ItemStruct(_, ref generics) => { |
| if !generics.is_parameterized() { |
| let ty = { |
| let tables = self.scx.tcx().tables.borrow(); |
| tables.node_types[&item.id] |
| }; |
| |
| if self.mode == TransItemCollectionMode::Eager { |
| debug!("RootCollector: ADT drop-glue for {}", |
| def_id_to_string(self.scx.tcx(), |
| self.scx.tcx().map.local_def_id(item.id))); |
| |
| let ty = glue::get_drop_glue_type(self.scx.tcx(), ty); |
| self.output.push(TransItem::DropGlue(DropGlueKind::Ty(ty))); |
| } |
| } |
| } |
| hir::ItemStatic(..) => { |
| debug!("RootCollector: ItemStatic({})", |
| def_id_to_string(self.scx.tcx(), |
| self.scx.tcx().map.local_def_id(item.id))); |
| self.output.push(TransItem::Static(item.id)); |
| } |
| hir::ItemConst(..) => { |
| debug!("RootCollector: ItemConst({})", |
| def_id_to_string(self.scx.tcx(), |
| self.scx.tcx().map.local_def_id(item.id))); |
| add_roots_for_const_item(self.scx, item.id, self.output); |
| } |
| hir::ItemFn(_, _, _, _, ref generics, _) => { |
| if !generics.is_type_parameterized() { |
| let def_id = self.scx.tcx().map.local_def_id(item.id); |
| |
| debug!("RootCollector: ItemFn({})", |
| def_id_to_string(self.scx.tcx(), def_id)); |
| |
| let instance = Instance::mono(self.scx, def_id); |
| self.output.push(TransItem::Fn(instance)); |
| } |
| } |
| } |
| |
| hir_visit::walk_item(self, item); |
| self.enclosing_item = old_enclosing_item; |
| } |
| |
| fn visit_impl_item(&mut self, ii: &'v hir::ImplItem) { |
| match ii.node { |
| hir::ImplItemKind::Method(hir::MethodSig { |
| ref generics, |
| .. |
| }, _) => { |
| let hir_map = &self.scx.tcx().map; |
| let parent_node_id = hir_map.get_parent_node(ii.id); |
| let is_impl_generic = match hir_map.expect_item(parent_node_id) { |
| &hir::Item { |
| node: hir::ItemImpl(_, _, ref generics, _, _, _), |
| .. |
| } => { |
| generics.is_type_parameterized() |
| } |
| _ => { |
| bug!() |
| } |
| }; |
| |
| if !generics.is_type_parameterized() && !is_impl_generic { |
| let def_id = self.scx.tcx().map.local_def_id(ii.id); |
| |
| debug!("RootCollector: MethodImplItem({})", |
| def_id_to_string(self.scx.tcx(), def_id)); |
| |
| let instance = Instance::mono(self.scx, def_id); |
| self.output.push(TransItem::Fn(instance)); |
| } |
| } |
| _ => { /* Nothing to do here */ } |
| } |
| |
| hir_visit::walk_impl_item(self, ii) |
| } |
| } |
| |
| fn create_trans_items_for_default_impls<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, |
| item: &'tcx hir::Item, |
| output: &mut Vec<TransItem<'tcx>>) { |
| match item.node { |
| hir::ItemImpl(_, |
| _, |
| ref generics, |
| _, |
| _, |
| ref items) => { |
| if generics.is_type_parameterized() { |
| return |
| } |
| |
| let impl_def_id = tcx.map.local_def_id(item.id); |
| |
| debug!("create_trans_items_for_default_impls(item={})", |
| def_id_to_string(tcx, impl_def_id)); |
| |
| if let Some(trait_ref) = tcx.impl_trait_ref(impl_def_id) { |
| let default_impls = tcx.provided_trait_methods(trait_ref.def_id); |
| let callee_substs = tcx.erase_regions(&trait_ref.substs); |
| let overridden_methods: FnvHashSet<_> = items.iter() |
| .map(|item| item.name) |
| .collect(); |
| for default_impl in default_impls { |
| if overridden_methods.contains(&default_impl.name) { |
| continue; |
| } |
| |
| if default_impl.generics.has_type_params(subst::FnSpace) { |
| continue; |
| } |
| |
| // The substitutions we have are on the impl, so we grab |
| // the method type from the impl to substitute into. |
| let mth = meth::get_impl_method(tcx, |
| impl_def_id, |
| callee_substs, |
| default_impl.name); |
| |
| assert!(mth.is_provided); |
| |
| let predicates = mth.method.predicates.predicates.subst(tcx, &mth.substs); |
| if !normalize_and_test_predicates(tcx, predicates.into_vec()) { |
| continue; |
| } |
| |
| if can_have_local_instance(tcx, default_impl.def_id) { |
| let empty_substs = tcx.erase_regions(&mth.substs); |
| let item = create_fn_trans_item(tcx, |
| default_impl.def_id, |
| callee_substs, |
| empty_substs); |
| output.push(item); |
| } |
| } |
| } |
| } |
| _ => { |
| bug!() |
| } |
| } |
| } |
| |
| // There are no translation items for constants themselves but their |
| // initializers might still contain something that produces translation items, |
| // such as cast that introduce a new vtable. |
| fn add_roots_for_const_item<'a, 'tcx>(scx: &SharedCrateContext<'a, 'tcx>, |
| const_item_node_id: NodeId, |
| output: &mut Vec<TransItem<'tcx>>) |
| { |
| let def_id = scx.tcx().map.local_def_id(const_item_node_id); |
| |
| // Scan the MIR in order to find function calls, closures, and |
| // drop-glue |
| let mir = errors::expect(scx.sess().diagnostic(), scx.get_mir(def_id), |
| || format!("Could not find MIR for const: {:?}", def_id)); |
| |
| let empty_substs = scx.empty_substs_for_def_id(def_id); |
| let visitor = MirNeighborCollector { |
| scx: scx, |
| mir: &mir, |
| output: output, |
| param_substs: empty_substs |
| }; |
| |
| visit_mir_and_promoted(visitor, &mir); |
| } |
| |
| fn visit_mir_and_promoted<'tcx, V: MirVisitor<'tcx>>(mut visitor: V, mir: &mir::Mir<'tcx>) { |
| visitor.visit_mir(&mir); |
| for promoted in &mir.promoted { |
| visitor.visit_mir(promoted); |
| } |
| } |
