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Merged
merged 12 commits into from
Oct 19, 2019
Merged

Prepare MutVisitors to handle interned projections #65197

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5de9cb0
super_ty on MutVisitor is empty so avoid the call
spastorino Oct 7, 2019
e069e9c
Prepare promote_consts MutVisitor to have projections interned
spastorino Oct 7, 2019
591cc9a
Prepare simplify MutVisitor to have projections interned
spastorino Oct 7, 2019
bb7d6d1
Prepare renumber MutVisitor to have projections interned
spastorino Oct 7, 2019
e3e9951
Prepare inline MutVisitor to have projections interned
spastorino Oct 7, 2019
0fc063f
Prepare generator MutVisitor to have projections interned
spastorino Oct 7, 2019
39c9ed3
Prepare erase_regions MutVisitor to have projections interned
spastorino Oct 7, 2019
2b2e35b
Prepare def_use MutVisitor to have projections interned
spastorino Oct 8, 2019
4f2a110
Remove unneeded callback and just use the new_local value
spastorino Oct 8, 2019
7fa3425
Setup a different visit place set of methods for mutable and immutabl…
spastorino Oct 8, 2019
d53fc9c
Add process_* place hooks to improve code reutilization
spastorino Oct 8, 2019
4834996
Use Cow to handle modifications of projection in preparation for inte…
spastorino Oct 9, 2019
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213 changes: 136 additions & 77 deletions src/librustc/mir/visit.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -158,22 +158,7 @@ macro_rules! make_mir_visitor {
self.super_place_base(base, context, location);
}

fn visit_projection(&mut self,
base: & $($mutability)? PlaceBase<'tcx>,
projection: & $($mutability)? [PlaceElem<'tcx>],
context: PlaceContext,
location: Location) {
self.super_projection(base, projection, context, location);
}

fn visit_projection_elem(&mut self,
base: & $($mutability)? PlaceBase<'tcx>,
proj_base: & $($mutability)? [PlaceElem<'tcx>],
elem: & $($mutability)? PlaceElem<'tcx>,
context: PlaceContext,
location: Location) {
self.super_projection_elem(base, proj_base, elem, context, location);
}
visit_place_fns!($($mutability)?);

fn visit_constant(&mut self,
constant: & $($mutability)? Constant<'tcx>,
Expand Down Expand Up @@ -681,28 +666,6 @@ macro_rules! make_mir_visitor {
);
}

fn super_place(&mut self,
place: & $($mutability)? Place<'tcx>,
context: PlaceContext,
location: Location) {
let mut context = context;

if !place.projection.is_empty() {
context = if context.is_mutating_use() {
PlaceContext::MutatingUse(MutatingUseContext::Projection)
} else {
PlaceContext::NonMutatingUse(NonMutatingUseContext::Projection)
};
}

self.visit_place_base(& $($mutability)? place.base, context, location);

self.visit_projection(& $($mutability)? place.base,
& $($mutability)? place.projection,
context,
location);
}

fn super_place_base(&mut self,
place_base: & $($mutability)? PlaceBase<'tcx>,
context: PlaceContext,
Expand All @@ -717,45 +680,6 @@ macro_rules! make_mir_visitor {
}
}

fn super_projection(&mut self,
base: & $($mutability)? PlaceBase<'tcx>,
projection: & $($mutability)? [PlaceElem<'tcx>],
context: PlaceContext,
location: Location) {
let mut cursor = projection;
while let [proj_base @ .., elem] = cursor {
cursor = proj_base;
self.visit_projection_elem(base, cursor, elem, context, location);
}
}

fn super_projection_elem(&mut self,
_base: & $($mutability)? PlaceBase<'tcx>,
_proj_base: & $($mutability)? [PlaceElem<'tcx>],
elem: & $($mutability)? PlaceElem<'tcx>,
_context: PlaceContext,
location: Location) {
match elem {
ProjectionElem::Field(_field, ty) => {
self.visit_ty(ty, TyContext::Location(location));
}
ProjectionElem::Index(local) => {
self.visit_local(
local,
PlaceContext::NonMutatingUse(NonMutatingUseContext::Copy),
location
);
}
ProjectionElem::Deref |
ProjectionElem::Subslice { from: _, to: _ } |
ProjectionElem::ConstantIndex { offset: _,
min_length: _,
from_end: _ } |
ProjectionElem::Downcast(_, _) => {
}
}
}

fn super_local_decl(&mut self,
local: Local,
local_decl: & $($mutability)? LocalDecl<'tcx>) {
Expand Down Expand Up @@ -858,6 +782,141 @@ macro_rules! make_mir_visitor {
}
}

macro_rules! visit_place_fns {
(mut) => (
fn super_place(
&mut self,
place: &mut Place<'tcx>,
context: PlaceContext,
location: Location,
) {
self.visit_place_base(&mut place.base, context, location);

if let Some(new_projection) = self.process_projection(&place.projection) {
place.projection = new_projection;
}
}

fn process_projection(
&mut self,
projection: &'a [PlaceElem<'tcx>],
) -> Option<Box<[PlaceElem<'tcx>]>> {
let mut projection = Cow::Borrowed(projection);

for i in 0..projection.len() {
if let Some(elem) = projection.get(i) {
if let Some(elem) = self.process_projection_elem(elem) {
let vec = projection.to_mut();
vec[i] = elem;
}
}
}

match projection {
Cow::Borrowed(_) => None,
Cow::Owned(vec) => Some(vec.into_boxed_slice()),
}
}

fn process_projection_elem(
&mut self,
_elem: &PlaceElem<'tcx>,
) -> Option<PlaceElem<'tcx>> {
None
}
);

() => (
fn visit_projection(
&mut self,
base: &PlaceBase<'tcx>,
projection: &[PlaceElem<'tcx>],
context: PlaceContext,
location: Location,
) {
self.super_projection(base, projection, context, location);
}

fn visit_projection_elem(
&mut self,
base: &PlaceBase<'tcx>,
proj_base: &[PlaceElem<'tcx>],
elem: &PlaceElem<'tcx>,
context: PlaceContext,
location: Location,
) {
self.super_projection_elem(base, proj_base, elem, context, location);
}

fn super_place(
&mut self,
place: &Place<'tcx>,
context: PlaceContext,
location: Location,
) {
let mut context = context;

if !place.projection.is_empty() {
context = if context.is_mutating_use() {
PlaceContext::MutatingUse(MutatingUseContext::Projection)
} else {
PlaceContext::NonMutatingUse(NonMutatingUseContext::Projection)
};
}

self.visit_place_base(&place.base, context, location);

self.visit_projection(&place.base,
&place.projection,
context,
location);
}

fn super_projection(
&mut self,
base: &PlaceBase<'tcx>,
projection: &[PlaceElem<'tcx>],
context: PlaceContext,
location: Location,
) {
let mut cursor = projection;
while let [proj_base @ .., elem] = cursor {
cursor = proj_base;
self.visit_projection_elem(base, cursor, elem, context, location);
}
}

fn super_projection_elem(
&mut self,
_base: &PlaceBase<'tcx>,
_proj_base: &[PlaceElem<'tcx>],
elem: &PlaceElem<'tcx>,
_context: PlaceContext,
location: Location,
) {
match elem {
ProjectionElem::Field(_field, ty) => {
self.visit_ty(ty, TyContext::Location(location));
}
ProjectionElem::Index(local) => {
self.visit_local(
local,
PlaceContext::NonMutatingUse(NonMutatingUseContext::Copy),
location
);
}
ProjectionElem::Deref |
ProjectionElem::Subslice { from: _, to: _ } |
ProjectionElem::ConstantIndex { offset: _,
min_length: _,
from_end: _ } |
ProjectionElem::Downcast(_, _) => {
}
}
}
);
}

make_mir_visitor!(Visitor,);
make_mir_visitor!(MutVisitor,mut);

Expand Down
17 changes: 16 additions & 1 deletion src/librustc_mir/borrow_check/nll/renumber.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,6 +1,6 @@
use rustc::ty::subst::SubstsRef;
use rustc::ty::{self, Ty, TypeFoldable};
use rustc::mir::{Location, Body, Promoted};
use rustc::mir::{Body, Location, PlaceElem, Promoted};
use rustc::mir::visit::{MutVisitor, TyContext};
use rustc::infer::{InferCtxt, NLLRegionVariableOrigin};
use rustc_index::vec::IndexVec;
Expand Down Expand Up @@ -62,6 +62,21 @@ impl<'a, 'tcx> MutVisitor<'tcx> for NLLVisitor<'a, 'tcx> {
debug!("visit_ty: ty={:?}", ty);
}

fn process_projection_elem(
&mut self,
elem: &PlaceElem<'tcx>,
) -> Option<PlaceElem<'tcx>> {
if let PlaceElem::Field(field, ty) = elem {
let new_ty = self.renumber_regions(ty);

if new_ty != *ty {
return Some(PlaceElem::Field(*field, new_ty));
}
}

None
}

fn visit_substs(&mut self, substs: &mut SubstsRef<'tcx>, location: Location) {
debug!("visit_substs(substs={:?}, location={:?})", substs, location);

Expand Down
16 changes: 15 additions & 1 deletion src/librustc_mir/transform/erase_regions.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -25,7 +25,6 @@ impl EraseRegionsVisitor<'tcx> {
impl MutVisitor<'tcx> for EraseRegionsVisitor<'tcx> {
fn visit_ty(&mut self, ty: &mut Ty<'tcx>, _: TyContext) {
*ty = self.tcx.erase_regions(ty);
self.super_ty(ty);
}

fn visit_region(&mut self, region: &mut ty::Region<'tcx>, _: Location) {
Expand All @@ -39,6 +38,21 @@ impl MutVisitor<'tcx> for EraseRegionsVisitor<'tcx> {
fn visit_substs(&mut self, substs: &mut SubstsRef<'tcx>, _: Location) {
*substs = self.tcx.erase_regions(substs);
}

fn process_projection_elem(
&mut self,
elem: &PlaceElem<'tcx>,
) -> Option<PlaceElem<'tcx>> {
if let PlaceElem::Field(field, ty) = elem {
let new_ty = self.tcx.erase_regions(ty);

if new_ty != *ty {
return Some(PlaceElem::Field(*field, new_ty));
}
}

None
}
}

pub struct EraseRegions;
Expand Down
46 changes: 39 additions & 7 deletions src/librustc_mir/transform/generator.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -88,6 +88,18 @@ impl<'tcx> MutVisitor<'tcx> for RenameLocalVisitor {
*local = self.to;
}
}

fn process_projection_elem(
&mut self,
elem: &PlaceElem<'tcx>,
) -> Option<PlaceElem<'tcx>> {
match elem {
PlaceElem::Index(local) if *local == self.from => {
Some(PlaceElem::Index(self.to))
}
_ => None,
}
}
}

struct DerefArgVisitor;
Expand All @@ -110,7 +122,13 @@ impl<'tcx> MutVisitor<'tcx> for DerefArgVisitor {
projection: Box::new([ProjectionElem::Deref]),
});
} else {
self.super_place(place, context, location);
self.visit_place_base(&mut place.base, context, location);

for elem in place.projection.iter() {
if let PlaceElem::Index(local) = elem {
assert_ne!(*local, self_arg());
}
}
}
}
}
Expand All @@ -137,7 +155,13 @@ impl<'tcx> MutVisitor<'tcx> for PinArgVisitor<'tcx> {
projection: Box::new([ProjectionElem::Field(Field::new(0), self.ref_gen_ty)]),
});
} else {
self.super_place(place, context, location);
self.visit_place_base(&mut place.base, context, location);

for elem in place.projection.iter() {
if let PlaceElem::Index(local) = elem {
assert_ne!(*local, self_arg());
}
}
}
}
}
Expand Down Expand Up @@ -247,17 +271,25 @@ impl MutVisitor<'tcx> for TransformVisitor<'tcx> {
assert_eq!(self.remap.get(local), None);
}

fn visit_place(&mut self,
place: &mut Place<'tcx>,
context: PlaceContext,
location: Location) {
fn visit_place(
&mut self,
place: &mut Place<'tcx>,
context: PlaceContext,
location: Location,
) {
if let PlaceBase::Local(l) = place.base {
// Replace an Local in the remap with a generator struct access
if let Some(&(ty, variant_index, idx)) = self.remap.get(&l) {
replace_base(place, self.make_field(variant_index, idx, ty));
}
} else {
self.super_place(place, context, location);
self.visit_place_base(&mut place.base, context, location);

for elem in place.projection.iter() {
if let PlaceElem::Index(local) = elem {
assert_ne!(*local, self_arg());
}
}
}
}

Expand Down
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