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Also generate StorageDead in constants
1 parent db85512 commit 84fe7cf

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10 files changed

+92
-57
lines changed

10 files changed

+92
-57
lines changed

‎compiler/rustc_mir/src/interpret/eval_context.rs‎

Lines changed: 6 additions & 16 deletions
Original file line numberDiff line numberDiff line change
@@ -4,7 +4,7 @@ use std::mem;
44

55
use rustc_data_structures::fx::FxHashMap;
66
use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
7-
use rustc_hir::{self as hir, def::DefKind, def_id::DefId, definitions::DefPathData};
7+
use rustc_hir::{self as hir, def_id::DefId, definitions::DefPathData};
88
use rustc_index::vec::IndexVec;
99
use rustc_macros::HashStable;
1010
use rustc_middle::ich::StableHashingContext;
@@ -700,21 +700,11 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
700700
let mut locals = IndexVec::from_elem(dummy, &body.local_decls);
701701

702702
// Now mark those locals as dead that we do not want to initialize
703-
match self.tcx.def_kind(instance.def_id()) {
704-
// statics and constants don't have `Storage*` statements, no need to look for them
705-
//
706-
// FIXME: The above is likely untrue. See
707-
// <https://github.com/rust-lang/rust/pull/70004#issuecomment-602022110>. Is it
708-
// okay to ignore `StorageDead`/`StorageLive` annotations during CTFE?
709-
DefKind::Static | DefKind::Const | DefKind::AssocConst => {}
710-
_ => {
711-
// Mark locals that use `Storage*` annotations as dead on function entry.
712-
let always_live = AlwaysLiveLocals::new(self.body());
713-
for local in locals.indices() {
714-
if !always_live.contains(local) {
715-
locals[local].value = LocalValue::Dead;
716-
}
717-
}
703+
// Mark locals that use `Storage*` annotations as dead on function entry.
704+
let always_live = AlwaysLiveLocals::new(self.body());
705+
for local in locals.indices() {
706+
if !always_live.contains(local) {
707+
locals[local].value = LocalValue::Dead;
718708
}
719709
}
720710
// done

‎compiler/rustc_mir_build/src/build/expr/as_operand.rs‎

Lines changed: 2 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -19,7 +19,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
1919
M: Mirror<'tcx, Output = Expr<'tcx>>,
2020
{
2121
let local_scope = self.local_scope();
22-
self.as_operand(block, local_scope, expr)
22+
self.as_operand(block, Some(local_scope), expr)
2323
}
2424

2525
/// Returns an operand suitable for use until the end of the current scope expression and
@@ -79,7 +79,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
7979
M: Mirror<'tcx, Output = Expr<'tcx>>,
8080
{
8181
let local_scope = self.local_scope();
82-
self.as_call_operand(block, local_scope, expr)
82+
self.as_call_operand(block, Some(local_scope), expr)
8383
}
8484

8585
/// Compile `expr` into a value that can be used as an operand.

‎compiler/rustc_mir_build/src/build/expr/as_rvalue.rs‎

Lines changed: 3 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -25,7 +25,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
2525
M: Mirror<'tcx, Output = Expr<'tcx>>,
2626
{
2727
let local_scope = self.local_scope();
28-
self.as_rvalue(block, local_scope, expr)
28+
self.as_rvalue(block, Some(local_scope), expr)
2929
}
3030

3131
/// Compile `expr`, yielding an rvalue.
@@ -445,9 +445,8 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
445445
Rvalue::Ref(this.hir.tcx().lifetimes.re_erased, borrow_kind, arg_place),
446446
);
447447

448-
// In constants, temp_lifetime is None. We should not need to drop
449-
// anything because no values with a destructor can be created in
450-
// a constant at this time, even if the type may need dropping.
448+
// See the comment in `expr_as_temp` and on the `rvalue_scopes` field for why
449+
// this can be `None`.
451450
if let Some(temp_lifetime) = temp_lifetime {
452451
this.schedule_drop_storage_and_value(upvar_span, temp_lifetime, temp);
453452
}

‎compiler/rustc_mir_build/src/build/expr/into.rs‎

Lines changed: 3 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -79,7 +79,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
7979

8080
// (#66975) Source could be a const of type `!`, so has to
8181
// exist in the generated MIR.
82-
unpack!(block = this.as_temp(block, this.local_scope(), source, Mutability::Mut,));
82+
unpack!(block = this.as_temp(block, Some(this.local_scope()), source, Mutability::Mut,));
8383

8484
// This is an optimization. If the expression was a call then we already have an
8585
// unreachable block. Don't bother to terminate it and create a new one.
@@ -300,7 +300,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
300300
// (evaluating them in order given by user)
301301
let fields_map: FxHashMap<_, _> = fields
302302
.into_iter()
303-
.map(|f| (f.name, unpack!(block = this.as_operand(block, scope, f.expr))))
303+
.map(|f| (f.name, unpack!(block = this.as_operand(block, Some(scope), f.expr))))
304304
.collect();
305305

306306
let field_names = this.hir.all_fields(adt_def, variant_index);
@@ -468,7 +468,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
468468

469469
ExprKind::Yield { value } => {
470470
let scope = this.local_scope();
471-
let value = unpack!(block = this.as_operand(block, scope, value));
471+
let value = unpack!(block = this.as_operand(block, Some(scope), value));
472472
let resume = this.cfg.start_new_block();
473473
this.record_operands_moved(slice::from_ref(&value));
474474
this.cfg.terminate(

‎compiler/rustc_mir_build/src/build/scope.rs‎

Lines changed: 8 additions & 32 deletions
Original file line numberDiff line numberDiff line change
@@ -85,7 +85,6 @@ use crate::build::matches::{ArmHasGuard, Candidate};
8585
use crate::build::{BlockAnd, BlockAndExtension, BlockFrame, Builder, CFG};
8686
use crate::thir::{Arm, Expr, ExprRef, LintLevel};
8787
use rustc_data_structures::fx::{FxHashMap, FxHashSet};
88-
use rustc_hir as hir;
8988
use rustc_index::vec::IndexVec;
9089
use rustc_middle::middle::region;
9190
use rustc_middle::mir::*;
@@ -740,18 +739,8 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
740739
/// We would allocate the box but then free it on the unwinding
741740
/// path; we would also emit a free on the 'success' path from
742741
/// panic, but that will turn out to be removed as dead-code.
743-
///
744-
/// When building statics/constants, returns `None` since
745-
/// intermediate values do not have to be dropped in that case.
746-
crate fn local_scope(&self) -> Option<region::Scope> {
747-
match self.hir.body_owner_kind {
748-
hir::BodyOwnerKind::Const | hir::BodyOwnerKind::Static(_) =>
749-
// No need to free storage in this context.
750-
{
751-
None
752-
}
753-
hir::BodyOwnerKind::Closure | hir::BodyOwnerKind::Fn => Some(self.scopes.topmost()),
754-
}
742+
crate fn local_scope(&self) -> region::Scope {
743+
self.scopes.topmost()
755744
}
756745

757746
// Scheduling drops
@@ -938,23 +927,13 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
938927
/// not the `DROP(_X)` itself, but the (spurious) unwind pathways
939928
/// that it creates. See #64391 for an example.
940929
crate fn record_operands_moved(&mut self, operands: &[Operand<'tcx>]) {
941-
let scope = match self.local_scope() {
942-
None => {
943-
// if there is no local scope, operands won't be dropped anyway
944-
return;
945-
}
930+
let local_scope = self.local_scope();
931+
let scope = self.scopes.scopes.last_mut().unwrap();
946932

947-
Some(local_scope) => {
948-
let top_scope = self.scopes.scopes.last_mut().unwrap();
949-
assert!(
950-
top_scope.region_scope == local_scope,
951-
"local scope ({:?}) is not the topmost scope!",
952-
local_scope
953-
);
954-
955-
top_scope
956-
}
957-
};
933+
assert_eq!(
934+
scope.region_scope, local_scope,
935+
"local scope is not the topmost scope!",
936+
);
958937

959938
// look for moves of a local variable, like `MOVE(_X)`
960939
let locals_moved = operands
@@ -993,9 +972,6 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
993972
match cond {
994973
// Don't try to drop a constant
995974
Operand::Constant(_) => (),
996-
// If constants and statics, we don't generate StorageLive for this
997-
// temporary, so don't try to generate StorageDead for it either.
998-
_ if self.local_scope().is_none() => (),
999975
Operand::Copy(place) | Operand::Move(place) => {
1000976
if let Some(cond_temp) = place.as_local() {
1001977
// Manually drop the condition on both branches.

‎src/test/mir-opt/const-promotion-extern-static.rs‎

Lines changed: 3 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -12,4 +12,7 @@ static mut BAR: *const &i32 = [&Y].as_ptr();
1212
// EMIT_MIR const_promotion_extern_static.FOO-promoted[0].ConstProp.after.mir
1313
static mut FOO: *const &i32 = [unsafe { &X }].as_ptr();
1414

15+
// EMIT_MIR const_promotion_extern_static.BOP.mir_map.0.mir
16+
static BOP: &i32 = &13;
17+
1518
fn main() {}

‎src/test/mir-opt/const_promotion_extern_static.BAR.PromoteTemps.diff‎

Lines changed: 3 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -33,6 +33,8 @@
3333
+ // + literal: Const { ty: &[&i32; 1], val: Unevaluated(WithOptConstParam { did: DefId(0:6 ~ const_promotion_extern_static[317d]::BAR), const_param_did: None }, [], Some(promoted[0])) }
3434
+ _2 = &(*_6); // scope 0 at $DIR/const-promotion-extern-static.rs:9:31: 9:35
3535
_1 = move _2 as &[&i32] (Pointer(Unsize)); // scope 0 at $DIR/const-promotion-extern-static.rs:9:31: 9:35
36+
- StorageDead(_4); // scope 0 at $DIR/const-promotion-extern-static.rs:9:34: 9:35
37+
StorageDead(_2); // scope 0 at $DIR/const-promotion-extern-static.rs:9:34: 9:35
3638
_0 = core::slice::<impl [&i32]>::as_ptr(move _1) -> [return: bb1, unwind: bb2]; // scope 0 at $DIR/const-promotion-extern-static.rs:9:31: 9:44
3739
// mir::Constant
3840
// + span: $DIR/const-promotion-extern-static.rs:9:36: 9:42
@@ -42,6 +44,7 @@
4244
bb1: {
4345
- StorageDead(_5); // scope 0 at $DIR/const-promotion-extern-static.rs:9:43: 9:44
4446
- StorageDead(_3); // scope 0 at $DIR/const-promotion-extern-static.rs:9:43: 9:44
47+
StorageDead(_1); // scope 0 at $DIR/const-promotion-extern-static.rs:9:43: 9:44
4548
return; // scope 0 at $DIR/const-promotion-extern-static.rs:9:1: 9:45
4649
}
4750

‎src/test/mir-opt/const_promotion_extern_static.BOP.mir_map.0.mir‎

Lines changed: 17 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,17 @@
1+
// MIR for `BOP` 0 mir_map
2+
3+
static BOP: &i32 = {
4+
let mut _0: &i32; // return place in scope 0 at $DIR/const-promotion-extern-static.rs:16:13: 16:17
5+
let _1: &i32; // in scope 0 at $DIR/const-promotion-extern-static.rs:16:20: 16:23
6+
let _2: i32; // in scope 0 at $DIR/const-promotion-extern-static.rs:16:21: 16:23
7+
8+
bb0: {
9+
StorageLive(_1); // scope 0 at $DIR/const-promotion-extern-static.rs:16:20: 16:23
10+
StorageLive(_2); // scope 0 at $DIR/const-promotion-extern-static.rs:16:21: 16:23
11+
_2 = const 13_i32; // scope 0 at $DIR/const-promotion-extern-static.rs:16:21: 16:23
12+
_1 = &_2; // scope 0 at $DIR/const-promotion-extern-static.rs:16:20: 16:23
13+
_0 = &(*_1); // scope 0 at $DIR/const-promotion-extern-static.rs:16:20: 16:23
14+
StorageDead(_1); // scope 0 at $DIR/const-promotion-extern-static.rs:16:22: 16:23
15+
return; // scope 0 at $DIR/const-promotion-extern-static.rs:16:1: 16:24
16+
}
17+
}

‎src/test/mir-opt/const_promotion_extern_static.FOO.PromoteTemps.diff‎

Lines changed: 3 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -35,6 +35,8 @@
3535
+ // + literal: Const { ty: &[&i32; 1], val: Unevaluated(WithOptConstParam { did: DefId(0:7 ~ const_promotion_extern_static[317d]::FOO), const_param_did: None }, [], Some(promoted[0])) }
3636
+ _2 = &(*_6); // scope 0 at $DIR/const-promotion-extern-static.rs:13:31: 13:46
3737
_1 = move _2 as &[&i32] (Pointer(Unsize)); // scope 0 at $DIR/const-promotion-extern-static.rs:13:31: 13:46
38+
- StorageDead(_4); // scope 0 at $DIR/const-promotion-extern-static.rs:13:45: 13:46
39+
StorageDead(_2); // scope 0 at $DIR/const-promotion-extern-static.rs:13:45: 13:46
3840
_0 = core::slice::<impl [&i32]>::as_ptr(move _1) -> [return: bb1, unwind: bb2]; // scope 0 at $DIR/const-promotion-extern-static.rs:13:31: 13:55
3941
// mir::Constant
4042
// + span: $DIR/const-promotion-extern-static.rs:13:47: 13:53
@@ -44,6 +46,7 @@
4446
bb1: {
4547
- StorageDead(_5); // scope 0 at $DIR/const-promotion-extern-static.rs:13:54: 13:55
4648
- StorageDead(_3); // scope 0 at $DIR/const-promotion-extern-static.rs:13:54: 13:55
49+
StorageDead(_1); // scope 0 at $DIR/const-promotion-extern-static.rs:13:54: 13:55
4750
return; // scope 0 at $DIR/const-promotion-extern-static.rs:13:1: 13:56
4851
}
4952

‎src/test/mir-opt/storage_live_dead_in_statics.XXX.mir_map.0.mir‎

Lines changed: 44 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -143,16 +143,60 @@ static XXX: &Foo = {
143143
StorageLive(_48); // scope 0 at $DIR/storage_live_dead_in_statics.rs:21:25: 21:31
144144
_48 = (const 0_u32, const 3_u32); // scope 0 at $DIR/storage_live_dead_in_statics.rs:21:25: 21:31
145145
_6 = [move _7, move _8, move _9, move _10, move _11, move _12, move _13, move _14, move _15, move _16, move _17, move _18, move _19, move _20, move _21, move _22, move _23, move _24, move _25, move _26, move _27, move _28, move _29, move _30, move _31, move _32, move _33, move _34, move _35, move _36, move _37, move _38, move _39, move _40, move _41, move _42, move _43, move _44, move _45, move _46, move _47, move _48]; // scope 0 at $DIR/storage_live_dead_in_statics.rs:7:12: 22:6
146+
StorageDead(_48); // scope 0 at $DIR/storage_live_dead_in_statics.rs:22:5: 22:6
147+
StorageDead(_47); // scope 0 at $DIR/storage_live_dead_in_statics.rs:22:5: 22:6
148+
StorageDead(_46); // scope 0 at $DIR/storage_live_dead_in_statics.rs:22:5: 22:6
149+
StorageDead(_45); // scope 0 at $DIR/storage_live_dead_in_statics.rs:22:5: 22:6
150+
StorageDead(_44); // scope 0 at $DIR/storage_live_dead_in_statics.rs:22:5: 22:6
151+
StorageDead(_43); // scope 0 at $DIR/storage_live_dead_in_statics.rs:22:5: 22:6
152+
StorageDead(_42); // scope 0 at $DIR/storage_live_dead_in_statics.rs:22:5: 22:6
153+
StorageDead(_41); // scope 0 at $DIR/storage_live_dead_in_statics.rs:22:5: 22:6
154+
StorageDead(_40); // scope 0 at $DIR/storage_live_dead_in_statics.rs:22:5: 22:6
155+
StorageDead(_39); // scope 0 at $DIR/storage_live_dead_in_statics.rs:22:5: 22:6
156+
StorageDead(_38); // scope 0 at $DIR/storage_live_dead_in_statics.rs:22:5: 22:6
157+
StorageDead(_37); // scope 0 at $DIR/storage_live_dead_in_statics.rs:22:5: 22:6
158+
StorageDead(_36); // scope 0 at $DIR/storage_live_dead_in_statics.rs:22:5: 22:6
159+
StorageDead(_35); // scope 0 at $DIR/storage_live_dead_in_statics.rs:22:5: 22:6
160+
StorageDead(_34); // scope 0 at $DIR/storage_live_dead_in_statics.rs:22:5: 22:6
161+
StorageDead(_33); // scope 0 at $DIR/storage_live_dead_in_statics.rs:22:5: 22:6
162+
StorageDead(_32); // scope 0 at $DIR/storage_live_dead_in_statics.rs:22:5: 22:6
163+
StorageDead(_31); // scope 0 at $DIR/storage_live_dead_in_statics.rs:22:5: 22:6
164+
StorageDead(_30); // scope 0 at $DIR/storage_live_dead_in_statics.rs:22:5: 22:6
165+
StorageDead(_29); // scope 0 at $DIR/storage_live_dead_in_statics.rs:22:5: 22:6
166+
StorageDead(_28); // scope 0 at $DIR/storage_live_dead_in_statics.rs:22:5: 22:6
167+
StorageDead(_27); // scope 0 at $DIR/storage_live_dead_in_statics.rs:22:5: 22:6
168+
StorageDead(_26); // scope 0 at $DIR/storage_live_dead_in_statics.rs:22:5: 22:6
169+
StorageDead(_25); // scope 0 at $DIR/storage_live_dead_in_statics.rs:22:5: 22:6
170+
StorageDead(_24); // scope 0 at $DIR/storage_live_dead_in_statics.rs:22:5: 22:6
171+
StorageDead(_23); // scope 0 at $DIR/storage_live_dead_in_statics.rs:22:5: 22:6
172+
StorageDead(_22); // scope 0 at $DIR/storage_live_dead_in_statics.rs:22:5: 22:6
173+
StorageDead(_21); // scope 0 at $DIR/storage_live_dead_in_statics.rs:22:5: 22:6
174+
StorageDead(_20); // scope 0 at $DIR/storage_live_dead_in_statics.rs:22:5: 22:6
175+
StorageDead(_19); // scope 0 at $DIR/storage_live_dead_in_statics.rs:22:5: 22:6
176+
StorageDead(_18); // scope 0 at $DIR/storage_live_dead_in_statics.rs:22:5: 22:6
177+
StorageDead(_17); // scope 0 at $DIR/storage_live_dead_in_statics.rs:22:5: 22:6
178+
StorageDead(_16); // scope 0 at $DIR/storage_live_dead_in_statics.rs:22:5: 22:6
179+
StorageDead(_15); // scope 0 at $DIR/storage_live_dead_in_statics.rs:22:5: 22:6
180+
StorageDead(_14); // scope 0 at $DIR/storage_live_dead_in_statics.rs:22:5: 22:6
181+
StorageDead(_13); // scope 0 at $DIR/storage_live_dead_in_statics.rs:22:5: 22:6
182+
StorageDead(_12); // scope 0 at $DIR/storage_live_dead_in_statics.rs:22:5: 22:6
183+
StorageDead(_11); // scope 0 at $DIR/storage_live_dead_in_statics.rs:22:5: 22:6
184+
StorageDead(_10); // scope 0 at $DIR/storage_live_dead_in_statics.rs:22:5: 22:6
185+
StorageDead(_9); // scope 0 at $DIR/storage_live_dead_in_statics.rs:22:5: 22:6
186+
StorageDead(_8); // scope 0 at $DIR/storage_live_dead_in_statics.rs:22:5: 22:6
187+
StorageDead(_7); // scope 0 at $DIR/storage_live_dead_in_statics.rs:22:5: 22:6
146188
_5 = &_6; // scope 0 at $DIR/storage_live_dead_in_statics.rs:7:11: 22:6
147189
_4 = &(*_5); // scope 0 at $DIR/storage_live_dead_in_statics.rs:7:11: 22:6
148190
_3 = move _4 as &[(u32, u32)] (Pointer(Unsize)); // scope 0 at $DIR/storage_live_dead_in_statics.rs:7:11: 22:6
191+
StorageDead(_4); // scope 0 at $DIR/storage_live_dead_in_statics.rs:22:5: 22:6
149192
_2 = Foo { tup: const "hi", data: move _3 }; // scope 0 at $DIR/storage_live_dead_in_statics.rs:5:29: 23:2
150193
// ty::Const
151194
// + ty: &str
152195
// + val: Value(Slice { data: Allocation { bytes: [104, 105], relocations: Relocations(SortedMap { data: [] }), init_mask: InitMask { blocks: [3], len: Size { raw: 2 } }, size: Size { raw: 2 }, align: Align { pow2: 0 }, mutability: Not, extra: () }, start: 0, end: 2 })
153196
// mir::Constant
154197
// + span: $DIR/storage_live_dead_in_statics.rs:6:10: 6:14
155198
// + literal: Const { ty: &str, val: Value(Slice { data: Allocation { bytes: [104, 105], relocations: Relocations(SortedMap { data: [] }), init_mask: InitMask { blocks: [3], len: Size { raw: 2 } }, size: Size { raw: 2 }, align: Align { pow2: 0 }, mutability: Not, extra: () }, start: 0, end: 2 }) }
199+
StorageDead(_3); // scope 0 at $DIR/storage_live_dead_in_statics.rs:23:1: 23:2
156200
_1 = &_2; // scope 0 at $DIR/storage_live_dead_in_statics.rs:5:28: 23:2
157201
_0 = &(*_1); // scope 0 at $DIR/storage_live_dead_in_statics.rs:5:28: 23:2
158202
StorageDead(_5); // scope 0 at $DIR/storage_live_dead_in_statics.rs:23:1: 23:2

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