Delay use of Place in favor of PlaceBuilder

This commit is contained in:
Roxane 2021-02-18 19:02:07 -05:00
parent ec10b71d42
commit d4f8729c89
9 changed files with 139 additions and 76 deletions

View File

@ -94,6 +94,14 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
)
);
}
// ROX:
//
// Where the handling of destructure patterns start
//
// let (a, b, c, _ ) = something
//
// (a, b, c, _) is the pattern
// something is the initializer
StmtKind::Let { remainder_scope, init_scope, pattern, initializer, lint_level } => {
let ignores_expr_result = matches!(*pattern.kind, PatKind::Wild);
this.block_context.push(BlockFrame::Statement { ignores_expr_result });
@ -125,6 +133,8 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
ArmHasGuard(false),
Some((None, initializer_span)),
);
// This is where we get into pattern handling of the let
// statement
this.expr_into_pattern(block, pattern.clone(), init)
})
}

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@ -10,6 +10,7 @@ use rustc_middle::hir::place::ProjectionKind as HirProjectionKind;
use rustc_middle::middle::region;
use rustc_middle::mir::AssertKind::BoundsCheck;
use rustc_middle::mir::*;
use rustc_middle::ty::AdtDef;
use rustc_middle::ty::{self, CanonicalUserTypeAnnotation, Ty, TyCtxt, Variance};
use rustc_span::Span;
use rustc_target::abi::VariantIdx;
@ -17,7 +18,7 @@ use rustc_target::abi::VariantIdx;
use rustc_index::vec::Idx;
/// The "outermost" place that holds this value.
#[derive(Copy, Clone, Debug)]
#[derive(Copy, Clone, Debug, PartialEq)]
crate enum PlaceBase {
/// Denotes the start of a `Place`.
Local(Local),
@ -67,7 +68,7 @@ crate enum PlaceBase {
///
/// This is used internally when building a place for an expression like `a.b.c`. The fields `b`
/// and `c` can be progressively pushed onto the place builder that is created when converting `a`.
#[derive(Clone, Debug)]
#[derive(Clone, Debug, PartialEq)]
crate struct PlaceBuilder<'tcx> {
base: PlaceBase,
projection: Vec<PlaceElem<'tcx>>,
@ -292,6 +293,7 @@ impl<'tcx> PlaceBuilder<'tcx> {
}
}
/// ROX: Function that will be called when we really do need a place
fn expect_upvars_resolved<'a>(
self,
tcx: TyCtxt<'tcx>,
@ -319,15 +321,22 @@ impl<'tcx> PlaceBuilder<'tcx> {
self.project(PlaceElem::Field(f, ty))
}
fn deref(self) -> Self {
crate fn deref(self) -> Self {
self.project(PlaceElem::Deref)
}
crate fn downcast(self, adt_def: &'tcx AdtDef, variant_index: VariantIdx) -> Self {
self.project(PlaceElem::Downcast(
Some(adt_def.variants[variant_index].ident.name),
variant_index,
))
}
fn index(self, index: Local) -> Self {
self.project(PlaceElem::Index(index))
}
fn project(mut self, elem: PlaceElem<'tcx>) -> Self {
crate fn project(mut self, elem: PlaceElem<'tcx>) -> Self {
self.projection.push(elem);
self
}
@ -367,6 +376,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
block.and(place_builder.into_place(self.tcx, self.typeck_results))
}
// ROX: As place builder
/// This is used when constructing a compound `Place`, so that we can avoid creating
/// intermediate `Place` values until we know the full set of projections.
crate fn as_place_builder(
@ -613,13 +623,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
// The "retagging" transformation (for Stacked Borrows) relies on this.
let idx = unpack!(block = self.as_temp(block, temp_lifetime, index, Mutability::Not,));
block = self.bounds_check(
block,
base_place.clone().into_place(self.tcx, self.typeck_results),
idx,
expr_span,
source_info,
);
block = self.bounds_check(block, base_place.clone(), idx, expr_span, source_info);
if is_outermost_index {
self.read_fake_borrows(block, fake_borrow_temps, source_info)
@ -640,7 +644,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
fn bounds_check(
&mut self,
block: BasicBlock,
slice: Place<'tcx>,
slice: PlaceBuilder<'tcx>,
index: Local,
expr_span: Span,
source_info: SourceInfo,
@ -652,7 +656,12 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
let lt = self.temp(bool_ty, expr_span);
// len = len(slice)
self.cfg.push_assign(block, source_info, len, Rvalue::Len(slice));
self.cfg.push_assign(
block,
source_info,
len,
Rvalue::Len(slice.clone().into_place(self.tcx, self.typeck_results)),
);
// lt = idx < len
self.cfg.push_assign(
block,

View File

@ -280,6 +280,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
let field_names: Vec<_> =
(0..adt_def.variants[variant_index].fields.len()).map(Field::new).collect();
// ROX: This is probably here the function record/struct update pattern is done.
let fields: Vec<_> = if let Some(FruInfo { base, field_types }) = base {
let place_builder = unpack!(block = this.as_place_builder(block, base));

View File

@ -62,7 +62,7 @@
mod as_constant;
mod as_operand;
mod as_place;
pub mod as_place;
mod as_rvalue;
mod as_temp;
mod category;

View File

@ -1,3 +1,6 @@
// ROX: this folder contains all code for handling patterns, including exhaustiveness checking etc.
// We want to be careful ^^'
//! Code related to match expressions. These are sufficiently complex to
//! warrant their own module and submodules. :) This main module includes the
//! high-level algorithm, the submodules contain the details.
@ -5,6 +8,7 @@
//! This also includes code for pattern bindings in `let` statements and
//! function parameters.
use crate::build::expr::as_place::PlaceBuilder;
use crate::build::scope::DropKind;
use crate::build::ForGuard::{self, OutsideGuard, RefWithinGuard};
use crate::build::{BlockAnd, BlockAndExtension, Builder};
@ -96,7 +100,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
let scrutinee_place =
unpack!(block = self.lower_scrutinee(block, scrutinee, scrutinee_span,));
let mut arm_candidates = self.create_match_candidates(scrutinee_place, &arms);
let mut arm_candidates = self.create_match_candidates(scrutinee_place.clone(), &arms);
let match_has_guard = arms.iter().any(|arm| arm.guard.is_some());
let mut candidates =
@ -121,8 +125,10 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
mut block: BasicBlock,
scrutinee: &Expr<'_, 'tcx>,
scrutinee_span: Span,
) -> BlockAnd<Place<'tcx>> {
let scrutinee_place = unpack!(block = self.as_place(block, scrutinee));
) -> BlockAnd<PlaceBuilder<'tcx>> {
let scrutinee_place_builder = unpack!(block = self.as_place_builder(block, scrutinee));
let scrutinee_place =
scrutinee_place_builder.clone().into_place(self.tcx, self.typeck_results);
// Matching on a `scrutinee_place` with an uninhabited type doesn't
// generate any memory reads by itself, and so if the place "expression"
// contains unsafe operations like raw pointer dereferences or union
@ -142,13 +148,13 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
let source_info = self.source_info(scrutinee_span);
self.cfg.push_fake_read(block, source_info, cause_matched_place, scrutinee_place);
block.and(scrutinee_place)
block.and(scrutinee_place_builder)
}
/// Create the initial `Candidate`s for a `match` expression.
fn create_match_candidates<'pat>(
&mut self,
scrutinee: Place<'tcx>,
scrutinee: PlaceBuilder<'tcx>,
arms: &'pat [Arm<'pat, 'tcx>],
) -> Vec<(&'pat Arm<'pat, 'tcx>, Candidate<'pat, 'tcx>)> {
// Assemble a list of candidates: there is one candidate per pattern,
@ -156,7 +162,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
arms.iter()
.map(|arm| {
let arm_has_guard = arm.guard.is_some();
let arm_candidate = Candidate::new(scrutinee, &arm.pattern, arm_has_guard);
let arm_candidate = Candidate::new(scrutinee.clone(), &arm.pattern, arm_has_guard);
(arm, arm_candidate)
})
.collect()
@ -222,7 +228,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
fn lower_match_arms(
&mut self,
destination: Place<'tcx>,
scrutinee_place: Place<'tcx>,
scrutinee_place: PlaceBuilder<'tcx>,
scrutinee_span: Span,
arm_candidates: Vec<(&'_ Arm<'_, 'tcx>, Candidate<'_, 'tcx>)>,
outer_source_info: SourceInfo,
@ -241,7 +247,12 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
arm.span,
&arm.pattern,
ArmHasGuard(arm.guard.is_some()),
Some((Some(&scrutinee_place), scrutinee_span)),
Some((
Some(
&scrutinee_place.clone().into_place(this.tcx, this.typeck_results),
),
scrutinee_span,
)),
);
let arm_block = this.bind_pattern(
@ -446,8 +457,17 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
}
_ => {
let place = unpack!(block = self.as_place(block, initializer));
self.place_into_pattern(block, irrefutable_pat, place, true)
// Converts the destruct pattern into a place
//
// We don't want to convert to a place right away
// because in case of such pattern inside a closure, the projections matching a
// captured place might have not been applied.
// [FIXME] Need to find where this is happening and make the necessary changes there once
// Candidate is modified
//
// We want to use a place builder; Maybe use `as_place_builder`
let place_builder = unpack!(block = self.as_place_builder(block, initializer));
self.place_into_pattern(block, irrefutable_pat, place_builder, true)
}
}
}
@ -456,9 +476,10 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
&mut self,
block: BasicBlock,
irrefutable_pat: Pat<'tcx>,
initializer: Place<'tcx>,
initializer: PlaceBuilder<'tcx>,
set_match_place: bool,
) -> BlockAnd<()> {
let place = initializer.clone().into_place(self.tcx, self.typeck_results);
let mut candidate = Candidate::new(initializer, &irrefutable_pat, false);
let fake_borrow_temps =
@ -478,7 +499,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
VarBindingForm { opt_match_place: Some((ref mut match_place, _)), .. },
)))) = self.local_decls[local].local_info
{
*match_place = Some(initializer);
*match_place = Some(place);
} else {
bug!("Let binding to non-user variable.")
}
@ -717,7 +738,7 @@ struct Candidate<'pat, 'tcx> {
}
impl<'tcx, 'pat> Candidate<'pat, 'tcx> {
fn new(place: Place<'tcx>, pattern: &'pat Pat<'tcx>, has_guard: bool) -> Self {
fn new(place: PlaceBuilder<'tcx>, pattern: &'pat Pat<'tcx>, has_guard: bool) -> Self {
Candidate {
span: pattern.span,
has_guard,
@ -791,7 +812,7 @@ struct Ascription<'tcx> {
#[derive(Clone, Debug)]
crate struct MatchPair<'pat, 'tcx> {
// this place...
place: Place<'tcx>,
place: PlaceBuilder<'tcx>,
// ... must match this pattern.
pattern: &'pat Pat<'tcx>,
@ -1198,7 +1219,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
&mut otherwise,
pats,
or_span,
place,
place.clone(),
fake_borrows,
);
});
@ -1224,12 +1245,14 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
otherwise: &mut Option<BasicBlock>,
pats: &'pat [Pat<'tcx>],
or_span: Span,
place: Place<'tcx>,
place: PlaceBuilder<'tcx>,
fake_borrows: &mut Option<FxHashSet<Place<'tcx>>>,
) {
debug!("test_or_pattern:\ncandidate={:#?}\npats={:#?}", candidate, pats);
let mut or_candidates: Vec<_> =
pats.iter().map(|pat| Candidate::new(place, pat, candidate.has_guard)).collect();
let mut or_candidates: Vec<_> = pats
.iter()
.map(|pat| Candidate::new(place.clone(), pat, candidate.has_guard))
.collect();
let mut or_candidate_refs: Vec<_> = or_candidates.iter_mut().collect();
let otherwise = if candidate.otherwise_block.is_some() {
&mut candidate.otherwise_block
@ -1412,7 +1435,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
// extract the match-pair from the highest priority candidate
let match_pair = &candidates.first().unwrap().match_pairs[0];
let mut test = self.test(match_pair);
let match_place = match_pair.place;
let match_place = match_pair.place.clone();
// most of the time, the test to perform is simply a function
// of the main candidate; but for a test like SwitchInt, we
@ -1428,7 +1451,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
}
TestKind::Switch { adt_def: _, ref mut variants } => {
for candidate in candidates.iter() {
if !self.add_variants_to_switch(&match_place, candidate, variants) {
if !self.add_variants_to_switch(&match_place.clone(), candidate, variants) {
break;
}
}
@ -1438,7 +1461,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
// Insert a Shallow borrow of any places that is switched on.
if let Some(fb) = fake_borrows {
fb.insert(match_place);
fb.insert(match_place.clone().into_place(self.tcx, self.typeck_results));
}
// perform the test, branching to one of N blocks. For each of
@ -1456,7 +1479,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
// encounter a candidate where the test is not relevant; at
// that point, we stop sorting.
while let Some(candidate) = candidates.first_mut() {
if let Some(idx) = self.sort_candidate(&match_place, &test, candidate) {
if let Some(idx) = self.sort_candidate(&match_place.clone(), &test, candidate) {
let (candidate, rest) = candidates.split_first_mut().unwrap();
target_candidates[idx].push(candidate);
candidates = rest;
@ -1519,7 +1542,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
target_blocks
};
self.perform_test(block, match_place, &test, make_target_blocks);
self.perform_test(block, match_place.clone(), &test, make_target_blocks);
}
/// Determine the fake borrows that are needed from a set of places that
@ -1753,11 +1776,13 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
}
Guard::IfLet(pat, scrutinee) => {
let scrutinee_span = scrutinee.span;
let scrutinee_place =
unpack!(block = self.lower_scrutinee(block, scrutinee, scrutinee_span));
let mut guard_candidate = Candidate::new(scrutinee_place, &pat, false);
let scrutinee_place = unpack!(
block = self.lower_scrutinee(block, scrutinee.clone(), scrutinee_span)
);
let mut guard_candidate = Candidate::new(scrutinee_place.clone(), &pat, false);
let wildcard = Pat::wildcard_from_ty(pat.ty);
let mut otherwise_candidate = Candidate::new(scrutinee_place, &wildcard, false);
let mut otherwise_candidate =
Candidate::new(scrutinee_place.clone(), &wildcard, false);
let fake_borrow_temps = self.lower_match_tree(
block,
pat.span,
@ -1769,7 +1794,10 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
pat.span.to(arm_span.unwrap()),
pat,
ArmHasGuard(false),
Some((Some(&scrutinee_place), scrutinee.span)),
Some((
Some(&scrutinee_place.clone().into_place(tcx, self.typeck_results)),
scrutinee.span,
)),
);
let post_guard_block = self.bind_pattern(
self.source_info(pat.span),

View File

@ -12,11 +12,11 @@
//! sort of test: for example, testing which variant an enum is, or
//! testing a value against a constant.
use crate::build::expr::as_place::PlaceBuilder;
use crate::build::matches::{Ascription, Binding, Candidate, MatchPair};
use crate::build::Builder;
use crate::thir::{self, *};
use rustc_hir::RangeEnd;
use rustc_middle::mir::Place;
use rustc_middle::ty;
use rustc_middle::ty::layout::IntegerExt;
use rustc_target::abi::{Integer, Size};
@ -68,11 +68,12 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
let match_pairs = mem::take(&mut candidate.match_pairs);
if let [MatchPair { pattern: Pat { kind: box PatKind::Or { pats }, .. }, place }] =
*match_pairs
&*match_pairs.clone()
{
existing_bindings.extend_from_slice(&new_bindings);
mem::swap(&mut candidate.bindings, &mut existing_bindings);
candidate.subcandidates = self.create_or_subcandidates(candidate, place, pats);
candidate.subcandidates =
self.create_or_subcandidates(candidate, place.clone(), pats);
return true;
}
@ -125,12 +126,12 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
fn create_or_subcandidates<'pat>(
&mut self,
candidate: &Candidate<'pat, 'tcx>,
place: Place<'tcx>,
place: PlaceBuilder<'tcx>,
pats: &'pat [Pat<'tcx>],
) -> Vec<Candidate<'pat, 'tcx>> {
pats.iter()
.map(|pat| {
let mut candidate = Candidate::new(place, pat, candidate.has_guard);
let mut candidate = Candidate::new(place.clone(), pat, candidate.has_guard);
self.simplify_candidate(&mut candidate);
candidate
})
@ -148,6 +149,9 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
candidate: &mut Candidate<'pat, 'tcx>,
) -> Result<(), MatchPair<'pat, 'tcx>> {
let tcx = self.tcx;
// Generate place to be used in Ascription
// Generate place to be used in Binding
let place = match_pair.place.clone().into_place(tcx, self.typeck_results);
match *match_pair.pattern.kind {
PatKind::AscribeUserType {
ref subpattern,
@ -158,7 +162,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
candidate.ascriptions.push(Ascription {
span: user_ty_span,
user_ty,
source: match_pair.place,
source: place,
variance,
});
@ -177,7 +181,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
name,
mutability,
span: match_pair.pattern.span,
source: match_pair.place,
source: place,
var_id: var,
var_ty: ty,
binding_mode: mode,
@ -264,8 +268,10 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
}) && (adt_def.did.is_local()
|| !adt_def.is_variant_list_non_exhaustive());
if irrefutable {
let place = tcx.mk_place_downcast(match_pair.place, adt_def, variant_index);
candidate.match_pairs.extend(self.field_match_pairs(place, subpatterns));
let place_builder = match_pair.place.downcast(adt_def, variant_index);
candidate
.match_pairs
.extend(self.field_match_pairs(place_builder, subpatterns));
Ok(())
} else {
Err(match_pair)
@ -290,8 +296,8 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
}
PatKind::Deref { ref subpattern } => {
let place = tcx.mk_place_deref(match_pair.place);
candidate.match_pairs.push(MatchPair::new(place, subpattern));
let place_builder = match_pair.place.deref();
candidate.match_pairs.push(MatchPair::new(place_builder, subpattern));
Ok(())
}

View File

@ -5,6 +5,7 @@
// identify what tests are needed, perform the tests, and then filter
// the candidates based on the result.
use crate::build::expr::as_place::PlaceBuilder;
use crate::build::matches::{Candidate, MatchPair, Test, TestKind};
use crate::build::Builder;
use crate::thir::pattern::compare_const_vals;
@ -81,7 +82,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
pub(super) fn add_cases_to_switch<'pat>(
&mut self,
test_place: &Place<'tcx>,
test_place: &PlaceBuilder<'tcx>,
candidate: &Candidate<'pat, 'tcx>,
switch_ty: Ty<'tcx>,
options: &mut FxIndexMap<&'tcx ty::Const<'tcx>, u128>,
@ -123,7 +124,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
pub(super) fn add_variants_to_switch<'pat>(
&mut self,
test_place: &Place<'tcx>,
test_place: &PlaceBuilder<'tcx>,
candidate: &Candidate<'pat, 'tcx>,
variants: &mut BitSet<VariantIdx>,
) -> bool {
@ -151,10 +152,11 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
pub(super) fn perform_test(
&mut self,
block: BasicBlock,
place: Place<'tcx>,
place_builder: PlaceBuilder<'tcx>,
test: &Test<'tcx>,
make_target_blocks: impl FnOnce(&mut Self) -> Vec<BasicBlock>,
) {
let place = place_builder.clone().into_place(self.tcx, self.typeck_results);
debug!(
"perform_test({:?}, {:?}: {:?}, {:?})",
block,
@ -481,7 +483,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
/// tighter match code if we do something a bit different.
pub(super) fn sort_candidate<'pat>(
&mut self,
test_place: &Place<'tcx>,
test_place: &PlaceBuilder<'tcx>,
test: &Test<'tcx>,
candidate: &mut Candidate<'pat, 'tcx>,
) -> Option<usize> {
@ -728,7 +730,6 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
candidate: &mut Candidate<'pat, 'tcx>,
) {
let match_pair = candidate.match_pairs.remove(match_pair_index);
let tcx = self.tcx;
// So, if we have a match-pattern like `x @ Enum::Variant(P1, P2)`,
// we want to create a set of derived match-patterns like
@ -737,10 +738,10 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
Some(adt_def.variants[variant_index].ident.name),
variant_index,
);
let downcast_place = tcx.mk_place_elem(match_pair.place, elem); // `(x as Variant)`
let downcast_place = match_pair.place.project(elem); // `(x as Variant)`
let consequent_match_pairs = subpatterns.iter().map(|subpattern| {
// e.g., `(x as Variant).0`
let place = tcx.mk_place_field(downcast_place, subpattern.field, subpattern.pattern.ty);
let place = downcast_place.clone().field(subpattern.field, subpattern.pattern.ty);
// e.g., `(x as Variant).0 @ P1`
MatchPair::new(place, &subpattern.pattern)
});

View File

@ -1,3 +1,4 @@
use crate::build::expr::as_place::PlaceBuilder;
use crate::build::matches::MatchPair;
use crate::build::Builder;
use crate::thir::*;
@ -9,13 +10,13 @@ use std::convert::TryInto;
impl<'a, 'tcx> Builder<'a, 'tcx> {
crate fn field_match_pairs<'pat>(
&mut self,
place: Place<'tcx>,
place: PlaceBuilder<'tcx>,
subpatterns: &'pat [FieldPat<'tcx>],
) -> Vec<MatchPair<'pat, 'tcx>> {
subpatterns
.iter()
.map(|fieldpat| {
let place = self.tcx.mk_place_field(place, fieldpat.field, fieldpat.pattern.ty);
let place = place.clone().field(fieldpat.field, fieldpat.pattern.ty);
MatchPair::new(place, &fieldpat.pattern)
})
.collect()
@ -24,13 +25,19 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
crate fn prefix_slice_suffix<'pat>(
&mut self,
match_pairs: &mut SmallVec<[MatchPair<'pat, 'tcx>; 1]>,
place: &Place<'tcx>,
place: &PlaceBuilder<'tcx>,
prefix: &'pat [Pat<'tcx>],
opt_slice: Option<&'pat Pat<'tcx>>,
suffix: &'pat [Pat<'tcx>],
) {
let tcx = self.tcx;
let (min_length, exact_size) = match place.ty(&self.local_decls, tcx).ty.kind() {
let (min_length, exact_size) = match place
.clone()
.into_place(tcx, self.typeck_results)
.ty(&self.local_decls, tcx)
.ty
.kind()
{
ty::Array(_, length) => (length.eval_usize(tcx, self.param_env), true),
_ => ((prefix.len() + suffix.len()).try_into().unwrap(), false),
};
@ -38,20 +45,17 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
match_pairs.extend(prefix.iter().enumerate().map(|(idx, subpattern)| {
let elem =
ProjectionElem::ConstantIndex { offset: idx as u64, min_length, from_end: false };
let place = tcx.mk_place_elem(*place, elem);
let place = place.clone().project(elem);
MatchPair::new(place, subpattern)
}));
if let Some(subslice_pat) = opt_slice {
let suffix_len = suffix.len() as u64;
let subslice = tcx.mk_place_elem(
*place,
ProjectionElem::Subslice {
from: prefix.len() as u64,
to: if exact_size { min_length - suffix_len } else { suffix_len },
from_end: !exact_size,
},
);
let subslice = place.clone().project(ProjectionElem::Subslice {
from: prefix.len() as u64,
to: if exact_size { min_length - suffix_len } else { suffix_len },
from_end: !exact_size,
});
match_pairs.push(MatchPair::new(subslice, subslice_pat));
}
@ -62,7 +66,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
min_length,
from_end: !exact_size,
};
let place = tcx.mk_place_elem(*place, elem);
let place = place.clone().project(elem);
MatchPair::new(place, subpattern)
}));
}
@ -91,7 +95,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
}
impl<'pat, 'tcx> MatchPair<'pat, 'tcx> {
crate fn new(place: Place<'tcx>, pattern: &'pat Pat<'tcx>) -> MatchPair<'pat, 'tcx> {
crate fn new(place: PlaceBuilder<'tcx>, pattern: &'pat Pat<'tcx>) -> MatchPair<'pat, 'tcx> {
MatchPair { place, pattern }
}
}

View File

@ -1,4 +1,5 @@
use crate::build;
use crate::build::expr::as_place::PlaceBuilder;
use crate::build::scope::DropKind;
use crate::thir::{build_thir, Arena, BindingMode, Expr, LintLevel, Pat, PatKind};
use rustc_attr::{self as attr, UnwindAttr};
@ -1004,7 +1005,10 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
matches::ArmHasGuard(false),
Some((Some(&place), span)),
);
unpack!(block = self.place_into_pattern(block, pattern, place, false));
let place_builder = PlaceBuilder::from(local);
unpack!(
block = self.place_into_pattern(block, pattern, place_builder, false)
);
}
}
self.source_scope = original_source_scope;