[dev-jonghoonpark]

This PR fixes a bug caused by the workaround introduced in JDK-6587674.

Problem

When a constant conditional expression is folded and the remaining expression (the null literal) has type BOT, convert() skips the cast because of the BOT check added in JDK-6587674. As a result, the static type of the conditional expression (String) is lost.

Fix

The workaround in JDK-6587674 was meant to avoid convert() casting to the type of a discarded class. That case no longer occurs after JDK-8314621: noClassDefIn prevents a constant condition from being folded when the discarded branch contains a class declaration, so the type of a discarded class can no longer reach convert() as pt.

This PR therefore removes the workaround, changing

if (tree.type == pt || tree.type.hasTag(BOT))
    return tree;

to

if (tree.type == pt) return tree;

in convert().

Testing

• Added a regression test based on the reproducer from the issue.
• langtools_javac tests pass.
• tier1 tests pass.

---

• I confirm that I make this contribution in accordance with the OpenJDK Interim AI Policy.

---

Progress

• Change must be properly reviewed (1 review required, with at least 1 Reviewer)
• Change must not contain extraneous whitespace
• Commit message must refer to an issue

Issue

• JDK-8394468: Compiler Bug "Invalid pool entry" (Bug - P3)

Reviewers

• Jan Lahoda (@lahodaj - Reviewer)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk.git pull/33555/head:pull/33555
$ git checkout pull/33555

Update a local copy of the PR:
$ git checkout pull/33555
$ git pull https://git.openjdk.org/jdk.git pull/33555/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 33555

View PR using the GUI difftool:
$ git pr show -t 33555

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk/pull/33555.diff

Using Webrev

Link to Webrev Comment

[bridgekeeper]

👋 Welcome back dev-jonghoonpark! A progress list of the required criteria for merging this PR into master will be added to the body of your pull request. There are additional pull request commands available for use with this pull request.

[openjdk]

@dev-jonghoonpark This change now passes all automated pre-integration checks.

ℹ️ This project also has non-automated pre-integration requirements. Please see the file CONTRIBUTING.md for details.

After integration, the commit message for the final commit will be:

8394468: Compiler Bug "Invalid pool entry"

Reviewed-by: jlahoda

You can use pull request commands such as /contributor and /issue to adjust it as needed.

At the time when this comment was updated there had been 20 new commits pushed to the master branch:

• 6a81b85: 8394466: Test runtime/jni/critical/SuspendInCritical.java fails with ZGC
• 830141d: 8394660: [Valhalla] C1 detection of unloaded array klasses must be updated
• 90b8588: 8392187: JFR: Use-after-free bug in CPU-time profiler can crash JVM
• ... and 17 more: https://git.openjdk.org/jdk/compare/fd8089e571c098eb59036be7e7ae60cc54c4170c...master

As there are no conflicts, your changes will automatically be rebased on top of these commits when integrating. If you prefer to avoid this automatic rebasing, please check the documentation for the /integrate command for further details.

As you do not have Committer status in this project an existing Committer must agree to sponsor your change. Possible candidates are the reviewers of this PR (@lahodaj) but any other Committer may sponsor as well.

➡️ To flag this PR as ready for integration with the above commit message, type /integrate in a new comment. (Afterwards, your sponsor types /sponsor in a new comment to perform the integration).

[openjdk]

@dev-jonghoonpark The following label will be automatically applied to this pull request:

• compiler

When this pull request is ready to be reviewed, an "RFR" email will be sent to the corresponding mailing list. If you would like to change these labels, use the /label pull request command.

[mlbridge]

Webrevs

• 01: Full - Incremental (5d037c48)
• 00: Full (086d6c45)

[lahodaj]

The fix seems sensible to me. But I would suggest to enhance the test, and also run the resulting class and verify behavior. Thanks!

[lahodaj]

Looks good to me, thanks!

[dev-jonghoonpark]

/integrate

[openjdk]

@dev-jonghoonpark
Your change (at version 5d037c4) is now ready to be sponsored by a Committer.

[lahodaj]

/sponsor

[openjdk]

Going to push as commit a0340ff.
Since your change was applied there have been 29 commits pushed to the master branch:

• 3289945: 8395895: [BACKOUT] ScopedValue: Unused GrowableArray allocation in JVM_FindScopedValueBindings
• 50d32ec: 8389366: SSLFlowDelegate writerCF is incorrectly initialized
• e249306: 8307970: Thread.start is slow with large number of threads
• ... and 26 more: https://git.openjdk.org/jdk/compare/fd8089e571c098eb59036be7e7ae60cc54c4170c...master

Your commit was automatically rebased without conflicts.

[openjdk]

@lahodaj @dev-jonghoonpark Pushed as commit a0340ff.

💡 You may see a message that your pull request was closed with unmerged commits. This can be safely ignored.