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Change scope of temporaries in match guards

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Each pattern in a match arm has its own copy of the match guard in MIR,
with its own temporary, so it has to be dropped before the the guards
are joined to the single copy of the arm.
This commit is contained in:
Matthew Jasper 2021-09-05 18:50:55 +01:00
parent 226e181b80
commit ad7f109bfa
10 changed files with 25 additions and 24 deletions
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2
compiler/rustc_mir_build/src/build/expr/into.rs
View file

@ -68,7 +68,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
let then_blk = unpack!(this.then_else_break(
block,
&this.thir[cond],
condition_scope,
Some(condition_scope),
condition_scope,
then_expr.span,
));

8
compiler/rustc_mir_build/src/build/matches/mod.rs
View file

@ -39,7 +39,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
&mut self,
mut block: BasicBlock,
expr: &Expr<'tcx>,
temp_scope: region::Scope,
temp_scope_override: Option<region::Scope>,
break_scope: region::Scope,
variable_scope_span: Span,
) -> BlockAnd<()> {
@ -53,7 +53,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
this.then_else_break(
block,
&this.thir[value],
temp_scope,
temp_scope_override,
break_scope,
variable_scope_span,
)
@ -63,6 +63,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
this.lower_let_expr(block, &this.thir[expr], pat, break_scope, variable_scope_span)
}
_ => {
let temp_scope = temp_scope_override.unwrap_or_else(|| this.local_scope());
let mutability = Mutability::Mut;
let place =
unpack!(block = this.as_temp(block, Some(temp_scope), expr, mutability));
@ -1948,7 +1949,6 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
}
let arm_span = arm_span.unwrap();
let arm_scope = self.local_scope();
let match_scope = match_scope.unwrap();
let mut guard_span = rustc_span::DUMMY_SP;
@ -1957,7 +1957,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
Guard::If(e) => {
let e = &this.thir[e];
guard_span = e.span;
this.then_else_break(block, e, arm_scope, match_scope, arm_span)
this.then_else_break(block, e, None, match_scope, arm_span)
}
Guard::IfLet(ref pat, scrutinee) => {
let s = &this.thir[scrutinee];

11
src/test/mir-opt/match_arm_scopes.complicated_match.SimplifyCfg-initial.after-ElaborateDrops.after.diff
View file

@ -93,7 +93,7 @@
+ bb6: {
_0 = const 3_i32; // scope 0 at $DIR/match-arm-scopes.rs:15:59: 15:60
StorageDead(_10); // scope 0 at $DIR/match-arm-scopes.rs:15:72: 15:73
StorageDead(_9); // scope 0 at $DIR/match-arm-scopes.rs:15:77: 15:78
StorageDead(_9); // scope 0 at $DIR/match-arm-scopes.rs:15:72: 15:73
- goto -> bb23; // scope 0 at no-location
+ goto -> bb20; // scope 0 at no-location
}
@ -108,6 +108,7 @@
- bb11: {
+ bb8: {
StorageDead(_10); // scope 0 at $DIR/match-arm-scopes.rs:15:72: 15:73
StorageDead(_9); // scope 0 at $DIR/match-arm-scopes.rs:15:72: 15:73
- FakeRead(ForMatchGuard, _3); // scope 0 at $DIR/match-arm-scopes.rs:15:72: 15:73
- FakeRead(ForMatchGuard, _4); // scope 0 at $DIR/match-arm-scopes.rs:15:72: 15:73
- FakeRead(ForGuardBinding, _6); // scope 0 at $DIR/match-arm-scopes.rs:15:72: 15:73
@ -123,7 +124,7 @@
- bb12: {
+ bb9: {
StorageDead(_10); // scope 0 at $DIR/match-arm-scopes.rs:15:72: 15:73
StorageDead(_9); // scope 0 at $DIR/match-arm-scopes.rs:15:77: 15:78
StorageDead(_9); // scope 0 at $DIR/match-arm-scopes.rs:15:72: 15:73
StorageDead(_8); // scope 0 at $DIR/match-arm-scopes.rs:15:77: 15:78
StorageDead(_6); // scope 0 at $DIR/match-arm-scopes.rs:15:77: 15:78
- falseEdge -> [real: bb2, imaginary: bb3]; // scope 0 at $DIR/match-arm-scopes.rs:15:42: 15:73
@ -149,7 +150,7 @@
+ bb11: {
_0 = const 3_i32; // scope 0 at $DIR/match-arm-scopes.rs:15:59: 15:60
StorageDead(_13); // scope 0 at $DIR/match-arm-scopes.rs:15:72: 15:73
StorageDead(_12); // scope 0 at $DIR/match-arm-scopes.rs:15:77: 15:78
StorageDead(_12); // scope 0 at $DIR/match-arm-scopes.rs:15:72: 15:73
- goto -> bb23; // scope 0 at no-location
+ goto -> bb20; // scope 0 at no-location
}
@ -164,6 +165,7 @@
- bb16: {
+ bb13: {
StorageDead(_13); // scope 0 at $DIR/match-arm-scopes.rs:15:72: 15:73
StorageDead(_12); // scope 0 at $DIR/match-arm-scopes.rs:15:72: 15:73
- FakeRead(ForMatchGuard, _3); // scope 0 at $DIR/match-arm-scopes.rs:15:72: 15:73
- FakeRead(ForMatchGuard, _4); // scope 0 at $DIR/match-arm-scopes.rs:15:72: 15:73
- FakeRead(ForGuardBinding, _6); // scope 0 at $DIR/match-arm-scopes.rs:15:72: 15:73
@ -179,7 +181,7 @@
- bb17: {
+ bb14: {
StorageDead(_13); // scope 0 at $DIR/match-arm-scopes.rs:15:72: 15:73
StorageDead(_12); // scope 0 at $DIR/match-arm-scopes.rs:15:77: 15:78
StorageDead(_12); // scope 0 at $DIR/match-arm-scopes.rs:15:72: 15:73
StorageDead(_8); // scope 0 at $DIR/match-arm-scopes.rs:15:77: 15:78
StorageDead(_6); // scope 0 at $DIR/match-arm-scopes.rs:15:77: 15:78
- falseEdge -> [real: bb4, imaginary: bb5]; // scope 0 at $DIR/match-arm-scopes.rs:15:42: 15:73
@ -190,7 +192,6 @@
+ bb15: {
StorageDead(_7); // scope 0 at $DIR/match-arm-scopes.rs:15:77: 15:78
StorageDead(_5); // scope 0 at $DIR/match-arm-scopes.rs:15:77: 15:78
StorageDead(_12); // scope 0 at $DIR/match-arm-scopes.rs:15:77: 15:78
StorageDead(_8); // scope 0 at $DIR/match-arm-scopes.rs:15:77: 15:78
StorageDead(_6); // scope 0 at $DIR/match-arm-scopes.rs:15:77: 15:78
- goto -> bb22; // scope 0 at $DIR/match-arm-scopes.rs:15:77: 15:78

4
src/test/mir-opt/match_false_edges.full_tested_match.PromoteTemps.after.mir
View file

@ -72,6 +72,7 @@ fn full_tested_match() -> () {
}
bb7: {
StorageDead(_7); // scope 0 at $DIR/match_false_edges.rs:16:26: 16:27
FakeRead(ForMatchGuard, _4); // scope 0 at $DIR/match_false_edges.rs:16:26: 16:27
FakeRead(ForGuardBinding, _6); // scope 0 at $DIR/match_false_edges.rs:16:26: 16:27
StorageLive(_5); // scope 0 at $DIR/match_false_edges.rs:16:14: 16:15
@ -81,13 +82,12 @@ fn full_tested_match() -> () {
_1 = (const 1_i32, move _8); // scope 2 at $DIR/match_false_edges.rs:16:31: 16:37
StorageDead(_8); // scope 2 at $DIR/match_false_edges.rs:16:36: 16:37
StorageDead(_5); // scope 0 at $DIR/match_false_edges.rs:16:36: 16:37
StorageDead(_7); // scope 0 at $DIR/match_false_edges.rs:16:36: 16:37
StorageDead(_6); // scope 0 at $DIR/match_false_edges.rs:16:36: 16:37
goto -> bb10; // scope 0 at $DIR/match_false_edges.rs:16:36: 16:37
}
bb8: {
StorageDead(_7); // scope 0 at $DIR/match_false_edges.rs:16:36: 16:37
StorageDead(_7); // scope 0 at $DIR/match_false_edges.rs:16:26: 16:27
StorageDead(_6); // scope 0 at $DIR/match_false_edges.rs:16:36: 16:37
goto -> bb3; // scope 0 at $DIR/match_false_edges.rs:16:20: 16:27
}

4
src/test/mir-opt/match_false_edges.full_tested_match2.PromoteTemps.before.mir
View file

@ -70,6 +70,7 @@ fn full_tested_match2() -> () {
}
bb7: {
StorageDead(_7); // scope 0 at $DIR/match_false_edges.rs:27:26: 27:27
FakeRead(ForMatchGuard, _4); // scope 0 at $DIR/match_false_edges.rs:27:26: 27:27
FakeRead(ForGuardBinding, _6); // scope 0 at $DIR/match_false_edges.rs:27:26: 27:27
StorageLive(_5); // scope 0 at $DIR/match_false_edges.rs:27:14: 27:15
@ -79,13 +80,12 @@ fn full_tested_match2() -> () {
_1 = (const 1_i32, move _8); // scope 2 at $DIR/match_false_edges.rs:27:31: 27:37
StorageDead(_8); // scope 2 at $DIR/match_false_edges.rs:27:36: 27:37
StorageDead(_5); // scope 0 at $DIR/match_false_edges.rs:27:36: 27:37
StorageDead(_7); // scope 0 at $DIR/match_false_edges.rs:27:36: 27:37
StorageDead(_6); // scope 0 at $DIR/match_false_edges.rs:27:36: 27:37
goto -> bb10; // scope 0 at $DIR/match_false_edges.rs:27:36: 27:37
}
bb8: {
StorageDead(_7); // scope 0 at $DIR/match_false_edges.rs:27:36: 27:37
StorageDead(_7); // scope 0 at $DIR/match_false_edges.rs:27:26: 27:27
StorageDead(_6); // scope 0 at $DIR/match_false_edges.rs:27:36: 27:37
falseEdge -> [real: bb3, imaginary: bb1]; // scope 0 at $DIR/match_false_edges.rs:27:20: 27:27
}

8
src/test/mir-opt/match_false_edges.main.PromoteTemps.before.mir
View file

@ -78,19 +78,19 @@ fn main() -> () {
}
bb7: {
StorageDead(_8); // scope 0 at $DIR/match_false_edges.rs:36:27: 36:28
FakeRead(ForMatchGuard, _5); // scope 0 at $DIR/match_false_edges.rs:36:27: 36:28
FakeRead(ForGuardBinding, _7); // scope 0 at $DIR/match_false_edges.rs:36:27: 36:28
StorageLive(_6); // scope 0 at $DIR/match_false_edges.rs:36:14: 36:16
_6 = ((_2 as Some).0: i32); // scope 0 at $DIR/match_false_edges.rs:36:14: 36:16
_1 = const 1_i32; // scope 2 at $DIR/match_false_edges.rs:36:32: 36:33
StorageDead(_6); // scope 0 at $DIR/match_false_edges.rs:36:32: 36:33
StorageDead(_8); // scope 0 at $DIR/match_false_edges.rs:36:32: 36:33
StorageDead(_7); // scope 0 at $DIR/match_false_edges.rs:36:32: 36:33
goto -> bb14; // scope 0 at $DIR/match_false_edges.rs:36:32: 36:33
}
bb8: {
StorageDead(_8); // scope 0 at $DIR/match_false_edges.rs:36:32: 36:33
StorageDead(_8); // scope 0 at $DIR/match_false_edges.rs:36:27: 36:28
StorageDead(_7); // scope 0 at $DIR/match_false_edges.rs:36:32: 36:33
falseEdge -> [real: bb1, imaginary: bb1]; // scope 0 at $DIR/match_false_edges.rs:36:21: 36:28
}
@ -122,20 +122,20 @@ fn main() -> () {
bb12: {
StorageDead(_13); // scope 0 at $DIR/match_false_edges.rs:38:28: 38:29
StorageDead(_12); // scope 0 at $DIR/match_false_edges.rs:38:28: 38:29
FakeRead(ForMatchGuard, _5); // scope 0 at $DIR/match_false_edges.rs:38:28: 38:29
FakeRead(ForGuardBinding, _11); // scope 0 at $DIR/match_false_edges.rs:38:28: 38:29
StorageLive(_10); // scope 0 at $DIR/match_false_edges.rs:38:14: 38:15
_10 = ((_2 as Some).0: i32); // scope 0 at $DIR/match_false_edges.rs:38:14: 38:15
_1 = const 3_i32; // scope 4 at $DIR/match_false_edges.rs:38:33: 38:34
StorageDead(_10); // scope 0 at $DIR/match_false_edges.rs:38:33: 38:34
StorageDead(_12); // scope 0 at $DIR/match_false_edges.rs:38:33: 38:34
StorageDead(_11); // scope 0 at $DIR/match_false_edges.rs:38:33: 38:34
goto -> bb14; // scope 0 at $DIR/match_false_edges.rs:38:33: 38:34
}
bb13: {
StorageDead(_13); // scope 0 at $DIR/match_false_edges.rs:38:28: 38:29
StorageDead(_12); // scope 0 at $DIR/match_false_edges.rs:38:33: 38:34
StorageDead(_12); // scope 0 at $DIR/match_false_edges.rs:38:28: 38:29
StorageDead(_11); // scope 0 at $DIR/match_false_edges.rs:38:33: 38:34
falseEdge -> [real: bb3, imaginary: bb3]; // scope 0 at $DIR/match_false_edges.rs:38:20: 38:29
}

4
src/test/mir-opt/match_test.main.SimplifyCfg-initial.after.mir
View file

@ -75,14 +75,14 @@ fn main() -> () {
}
bb10: {
StorageDead(_9); // scope 2 at $DIR/match_test.rs:13:18: 13:19
FakeRead(ForMatchGuard, _8); // scope 2 at $DIR/match_test.rs:13:18: 13:19
_3 = const 0_i32; // scope 2 at $DIR/match_test.rs:13:23: 13:24
StorageDead(_9); // scope 2 at $DIR/match_test.rs:13:23: 13:24
goto -> bb14; // scope 2 at $DIR/match_test.rs:13:23: 13:24
}
bb11: {
StorageDead(_9); // scope 2 at $DIR/match_test.rs:13:23: 13:24
StorageDead(_9); // scope 2 at $DIR/match_test.rs:13:18: 13:19
falseEdge -> [real: bb3, imaginary: bb6]; // scope 2 at $DIR/match_test.rs:13:18: 13:19
}

2
src/test/mir-opt/matches_reduce_branches.match_nested_if.MatchBranchSimplification.32bit.diff
View file

@ -66,7 +66,7 @@
+ _7 = move _2; // scope 0 at $DIR/matches_reduce_branches.rs:41:18: 41:76
StorageDead(_2); // scope 0 at $DIR/matches_reduce_branches.rs:45:9: 45:10
- _1 = const true; // scope 0 at $DIR/matches_reduce_branches.rs:47:13: 47:17
- goto -> bb9; // scope 0 at $DIR/matches_reduce_branches.rs:48:9: 48:10
- goto -> bb9; // scope 0 at $DIR/matches_reduce_branches.rs:47:13: 47:17
- }
-
- bb8: {

2
src/test/mir-opt/matches_reduce_branches.match_nested_if.MatchBranchSimplification.64bit.diff
View file

@ -66,7 +66,7 @@
+ _7 = move _2; // scope 0 at $DIR/matches_reduce_branches.rs:41:18: 41:76
StorageDead(_2); // scope 0 at $DIR/matches_reduce_branches.rs:45:9: 45:10
- _1 = const true; // scope 0 at $DIR/matches_reduce_branches.rs:47:13: 47:17
- goto -> bb9; // scope 0 at $DIR/matches_reduce_branches.rs:48:9: 48:10
- goto -> bb9; // scope 0 at $DIR/matches_reduce_branches.rs:47:13: 47:17
- }
-
- bb8: {

4
src/test/mir-opt/remove_fake_borrows.match_guard.CleanupNonCodegenStatements.diff
View file

@ -47,6 +47,7 @@
}
bb5: {
StorageDead(_8); // scope 0 at $DIR/remove_fake_borrows.rs:8:20: 8:21
- FakeRead(ForMatchGuard, _4); // scope 0 at $DIR/remove_fake_borrows.rs:8:20: 8:21
- FakeRead(ForMatchGuard, _5); // scope 0 at $DIR/remove_fake_borrows.rs:8:20: 8:21
- FakeRead(ForMatchGuard, _6); // scope 0 at $DIR/remove_fake_borrows.rs:8:20: 8:21
@ -56,12 +57,11 @@
+ nop; // scope 0 at $DIR/remove_fake_borrows.rs:8:20: 8:21
+ nop; // scope 0 at $DIR/remove_fake_borrows.rs:8:20: 8:21
_0 = const 0_i32; // scope 0 at $DIR/remove_fake_borrows.rs:8:25: 8:26
StorageDead(_8); // scope 0 at $DIR/remove_fake_borrows.rs:8:25: 8:26
goto -> bb7; // scope 0 at $DIR/remove_fake_borrows.rs:8:25: 8:26
}
bb6: {
StorageDead(_8); // scope 0 at $DIR/remove_fake_borrows.rs:8:25: 8:26
StorageDead(_8); // scope 0 at $DIR/remove_fake_borrows.rs:8:20: 8:21
goto -> bb1; // scope 0 at $DIR/remove_fake_borrows.rs:8:20: 8:21
}