bjoernager/rust
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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];