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Adjust error yield/await lowering

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This commit is contained in:
Michael Goulet
2024-02-27 03:14:55 +00:00
parent fc3800f657
commit e0a726ca4b
3 changed files with 64 additions and 9 deletions
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52
compiler/rustc_ast_lowering/src/expr.rs
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@@ -764,10 +764,28 @@ impl<'hir> LoweringContext<'_, 'hir> {
Some(hir::CoroutineKind::Coroutine(_))
| Some(hir::CoroutineKind::Desugared(hir::CoroutineDesugaring::Gen, _))
| None => {
return hir::ExprKind::Err(self.dcx().emit_err(AwaitOnlyInAsyncFnAndBlocks {
await_kw_span,
item_span: self.current_item,
}));
// Lower to a block `{ EXPR; <error> }` so that the awaited expr
// is not accidentally orphaned.
let stmt_id = self.next_id();
let expr_err = self.expr(
expr.span,
hir::ExprKind::Err(self.dcx().emit_err(AwaitOnlyInAsyncFnAndBlocks {
await_kw_span,
item_span: self.current_item,
})),
);
return hir::ExprKind::Block(
self.block_all(
expr.span,
arena_vec![self; hir::Stmt {
hir_id: stmt_id,
kind: hir::StmtKind::Semi(expr),
span: expr.span,
}],
Some(self.arena.alloc(expr_err)),
),
None,
);
}
};
@@ -1500,12 +1518,31 @@ impl<'hir> LoweringContext<'_, 'hir> {
}
fn lower_expr_yield(&mut self, span: Span, opt_expr: Option<&Expr>) -> hir::ExprKind<'hir> {
let yielded =
opt_expr.as_ref().map(|x| self.lower_expr(x)).unwrap_or_else(|| self.expr_unit(span));
let is_async_gen = match self.coroutine_kind {
Some(hir::CoroutineKind::Desugared(hir::CoroutineDesugaring::Gen, _)) => false,
Some(hir::CoroutineKind::Desugared(hir::CoroutineDesugaring::AsyncGen, _)) => true,
Some(hir::CoroutineKind::Desugared(hir::CoroutineDesugaring::Async, _)) => {
return hir::ExprKind::Err(
self.dcx().emit_err(AsyncCoroutinesNotSupported { span }),
// Lower to a block `{ EXPR; <error> }` so that the awaited expr
// is not accidentally orphaned.
let stmt_id = self.next_id();
let expr_err = self.expr(
yielded.span,
hir::ExprKind::Err(self.dcx().emit_err(AsyncCoroutinesNotSupported { span })),
);
return hir::ExprKind::Block(
self.block_all(
yielded.span,
arena_vec![self; hir::Stmt {
hir_id: stmt_id,
kind: hir::StmtKind::Semi(yielded),
span: yielded.span,
}],
Some(self.arena.alloc(expr_err)),
),
None,
);
}
Some(hir::CoroutineKind::Coroutine(_)) => {
@@ -1535,9 +1572,6 @@ impl<'hir> LoweringContext<'_, 'hir> {
}
};
let yielded =
opt_expr.as_ref().map(|x| self.lower_expr(x)).unwrap_or_else(|| self.expr_unit(span));
if is_async_gen {
// `yield $expr` is transformed into `task_context = yield async_gen_ready($expr)`.
// This ensures that we store our resumed `ResumeContext` correctly, and also that