bjoernager/rust
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Use precise places when lowering Closures in THIR

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- Closures now use closure_min_captures to figure out captured paths
- Build upvar_mutbls using closure_min_captures
- Change logic in limit_capture_mutability to differentiate b/w
  capturing parent's local variable or capturing a variable that is
  captured by the parent (in case of nested closure) using PlaceBase.

Co-authored-by: Roxane Fruytier <roxane.fruytier@hotmail.com>
This commit is contained in:
Aman Arora 2020-11-26 00:07:41 -05:00
parent 6a1d0699a4
commit e2efdd156b
4 changed files with 107 additions and 61 deletions
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22
compiler/rustc_mir_build/src/build/mod.rs
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@ -10,6 +10,7 @@ use rustc_hir::lang_items::LangItem;
use rustc_hir::{GeneratorKind, HirIdMap, Node};
use rustc_index::vec::{Idx, IndexVec};
use rustc_infer::infer::TyCtxtInferExt;
use rustc_middle::hir::place::PlaceBase as HirPlaceBase;
use rustc_middle::middle::region;
use rustc_middle::mir::*;
use rustc_middle::ty::subst::Subst;
@ -823,7 +824,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
// with the closure's DefId. Here, we run through that vec of UpvarIds for
// the given closure and use the necessary information to create upvar
// debuginfo and to fill `self.upvar_mutbls`.
if let Some(upvars) = hir_typeck_results.closure_captures.get(&fn_def_id) {
if hir_typeck_results.closure_min_captures.get(&fn_def_id).is_some() {
let closure_env_arg = Local::new(1);
let mut closure_env_projs = vec![];
let mut closure_ty = self.local_decls[closure_env_arg].ty;
@ -836,14 +837,23 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
ty::Generator(_, substs, _) => ty::UpvarSubsts::Generator(substs),
_ => span_bug!(self.fn_span, "upvars with non-closure env ty {:?}", closure_ty),
};
let upvar_tys = upvar_substs.upvar_tys();
let upvars_with_tys = upvars.iter().zip(upvar_tys);
self.upvar_mutbls = upvars_with_tys
let capture_tys = upvar_substs.upvar_tys();
let captures_with_tys = hir_typeck_results
.closure_min_captures_flattened(fn_def_id)
.zip(capture_tys);
self.upvar_mutbls = captures_with_tys
.enumerate()
.map(|(i, ((&var_id, &upvar_id), ty))| {
let capture = hir_typeck_results.upvar_capture(upvar_id);
.map(|(i, (captured_place, ty))| {
let capture = captured_place.info.capture_kind;
let var_id = match captured_place.place.base {
HirPlaceBase::Upvar(upvar_id) => upvar_id.var_path.hir_id,
_ => bug!("Expected an upvar")
};
let mut mutability = Mutability::Not;
// FIXME(project-rfc-2229#8): Store more precise information
let mut name = kw::Invalid;
if let Some(Node::Binding(pat)) = tcx_hir.find(var_id) {
if let hir::PatKind::Binding(_, _, ident, _) = pat.kind {