Files
carbon-lang/toolchain/check/handle_expr_statement.cpp
Richard Smith 703529fc55 Destroy temporaries at the end of expression statements. (#7513)
Instead of tracking the cleanup scope depth on entry to each scope,
track an "ambient" cleanup scope depth that's *after* the destructors of
local variables in that scope. This gets increased to include the
destructors of local variables when we create a name-binding
declaration. Then, when we reach a point where temporaries should be
destroyed, run cleanups that are after the ambient cleanup scope depth
on the stack. This happens:

* At the `;` of a statement expression.
* At the `)` of an `if` or `while` statement.
* After performing the implied `HasValue()` call in a `for` statement.

Per informal agreement with leads, this means we lifetime-extend all
temporaries created in the initializer of a name-binding declaration to
the full scope of that declaration, but that temporaries created in an
expression statement are destroyed at the `;`.
2026-07-16 15:12:39 +00:00

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// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
// Exceptions. See /LICENSE for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
#include "toolchain/check/context.h"
#include "toolchain/check/control_flow.h"
#include "toolchain/check/convert.h"
#include "toolchain/check/handle.h"
#include "toolchain/sem_ir/inst.h"
namespace Carbon::Check {
auto HandleParseNode(Context& context, Parse::ExprStatementId /*node_id*/)
-> bool {
DiscardExpr(context, context.node_stack().PopExpr());
AddAndDiscardTemporaryCleanups(context);
return true;
}
} // namespace Carbon::Check