141 lines
4.8 KiB
Rust
141 lines
4.8 KiB
Rust
// Copyright 2017 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.
|
|
|
|
use rustc::ty::subst::Substs;
|
|
use rustc::ty::{self, CanonicalTy, ClosureSubsts, GeneratorSubsts, Ty, TypeFoldable};
|
|
use rustc::mir::{BasicBlock, Local, Location, Mir, Statement, StatementKind};
|
|
use rustc::mir::visit::{MutVisitor, TyContext};
|
|
use rustc::infer::{InferCtxt, NLLRegionVariableOrigin};
|
|
|
|
/// Replaces all free regions appearing in the MIR with fresh
|
|
/// inference variables, returning the number of variables created.
|
|
pub fn renumber_mir<'tcx>(infcx: &InferCtxt<'_, '_, 'tcx>, mir: &mut Mir<'tcx>) {
|
|
debug!("renumber_mir()");
|
|
debug!("renumber_mir: mir.arg_count={:?}", mir.arg_count);
|
|
|
|
let mut visitor = NLLVisitor { infcx };
|
|
visitor.visit_mir(mir);
|
|
}
|
|
|
|
/// Replaces all regions appearing in `value` with fresh inference
|
|
/// variables.
|
|
pub fn renumber_regions<'tcx, T>(
|
|
infcx: &InferCtxt<'_, '_, 'tcx>,
|
|
ty_context: TyContext,
|
|
value: &T,
|
|
) -> T
|
|
where
|
|
T: TypeFoldable<'tcx>,
|
|
{
|
|
debug!("renumber_regions(value={:?})", value);
|
|
|
|
infcx
|
|
.tcx
|
|
.fold_regions(value, &mut false, |_region, _depth| {
|
|
let origin = NLLRegionVariableOrigin::Inferred(ty_context);
|
|
infcx.next_nll_region_var(origin)
|
|
})
|
|
}
|
|
|
|
struct NLLVisitor<'a, 'gcx: 'a + 'tcx, 'tcx: 'a> {
|
|
infcx: &'a InferCtxt<'a, 'gcx, 'tcx>,
|
|
}
|
|
|
|
impl<'a, 'gcx, 'tcx> NLLVisitor<'a, 'gcx, 'tcx> {
|
|
fn renumber_regions<T>(&mut self, ty_context: TyContext, value: &T) -> T
|
|
where
|
|
T: TypeFoldable<'tcx>,
|
|
{
|
|
renumber_regions(self.infcx, ty_context, value)
|
|
}
|
|
}
|
|
|
|
impl<'a, 'gcx, 'tcx> MutVisitor<'tcx> for NLLVisitor<'a, 'gcx, 'tcx> {
|
|
fn visit_ty(&mut self, ty: &mut Ty<'tcx>, ty_context: TyContext) {
|
|
debug!("visit_ty(ty={:?}, ty_context={:?})", ty, ty_context);
|
|
|
|
*ty = self.renumber_regions(ty_context, ty);
|
|
|
|
debug!("visit_ty: ty={:?}", ty);
|
|
}
|
|
|
|
fn visit_substs(&mut self, substs: &mut &'tcx Substs<'tcx>, location: Location) {
|
|
debug!("visit_substs(substs={:?}, location={:?})", substs, location);
|
|
|
|
let ty_context = TyContext::Location(location);
|
|
*substs = self.renumber_regions(ty_context, &{ *substs });
|
|
|
|
debug!("visit_substs: substs={:?}", substs);
|
|
}
|
|
|
|
fn visit_region(&mut self, region: &mut ty::Region<'tcx>, location: Location) {
|
|
debug!("visit_region(region={:?}, location={:?})", region, location);
|
|
|
|
let old_region = *region;
|
|
let ty_context = TyContext::Location(location);
|
|
*region = self.renumber_regions(ty_context, &old_region);
|
|
|
|
debug!("visit_region: region={:?}", region);
|
|
}
|
|
|
|
fn visit_const(&mut self, constant: &mut &'tcx ty::Const<'tcx>, location: Location) {
|
|
let ty_context = TyContext::Location(location);
|
|
*constant = self.renumber_regions(ty_context, &*constant);
|
|
}
|
|
|
|
fn visit_generator_substs(&mut self,
|
|
substs: &mut GeneratorSubsts<'tcx>,
|
|
location: Location) {
|
|
debug!(
|
|
"visit_generator_substs(substs={:?}, location={:?})",
|
|
substs,
|
|
location,
|
|
);
|
|
|
|
let ty_context = TyContext::Location(location);
|
|
*substs = self.renumber_regions(ty_context, substs);
|
|
|
|
debug!("visit_generator_substs: substs={:?}", substs);
|
|
}
|
|
|
|
fn visit_closure_substs(&mut self, substs: &mut ClosureSubsts<'tcx>, location: Location) {
|
|
debug!(
|
|
"visit_closure_substs(substs={:?}, location={:?})",
|
|
substs,
|
|
location
|
|
);
|
|
|
|
let ty_context = TyContext::Location(location);
|
|
*substs = self.renumber_regions(ty_context, substs);
|
|
|
|
debug!("visit_closure_substs: substs={:?}", substs);
|
|
}
|
|
|
|
fn visit_user_assert_ty(&mut self, _c_ty: &mut CanonicalTy<'tcx>, _local: &mut Local,
|
|
_location: Location) {
|
|
// User-assert-ty statements represent types that the user added explicitly.
|
|
// We don't want to erase the regions from these types: rather, we want to
|
|
// add them as constraints at type-check time.
|
|
debug!("visit_user_assert_ty: skipping renumber");
|
|
}
|
|
|
|
fn visit_statement(
|
|
&mut self,
|
|
block: BasicBlock,
|
|
statement: &mut Statement<'tcx>,
|
|
location: Location,
|
|
) {
|
|
if let StatementKind::EndRegion(_) = statement.kind {
|
|
statement.kind = StatementKind::Nop;
|
|
}
|
|
self.super_statement(block, statement, location);
|
|
}
|
|
}
|