tarantool / luajit / 7118964921

89%

tarantool/master: 93%

Build Type

push

github

Committed by igormunkin

Commit Message

Fix HREFK forwarding vs. table.clear().

Reported by XmiliaH.

(cherry-picked from commit d5a237eae)

When performing HREFK (and also ALOAD, HLOAD) forwarding optimization,
the `table.clear()` function call may be performed on the table operand
from HREFK between table creation and IR, from which value is forwarded.
This call isn't taken in the account, so it may lead to too optimistic
value-forwarding from NEWREF (and also ASTORE, HSTORE), or the omitted
type guard for HREFK operation. Therefore, this leads to incorrect trace
behaviour (for example, taking a non-nil value from the cleared table).

This patch adds necessary checks for `table.clear()` calls.

Sergey Kaplun:
* added the description and the test for the problem

Part of tarantool/tarantool#9145

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14 existing lines in 3 files now uncovered.

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