8365296: Build failure with Clang due to -Wformat warning after JDK-8364611

[hgqxjj]

This issue is related to the definition of __sigset_t (__sigset_t act.sa_mask). In the glibc source, __sigset_t is defined in multiple places:

• bits/types/__sigset_t.h

• sysdeps/unix/sysv/linux/bits/types/__sigset_t.h (introduced after glibc 2.25)

During compilation with Clang, the latter definition appears to be used, where __sigset_t is a struct, causing the printf("%X", act.sa_mask) to fail.

we can detect whether _SIGSET_NWORDS is defined and handle the printing differently based on that, ensuring correct handling of the struct type.

---

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Issue

• JDK-8365296: Build failure with Clang due to -Wformat warning after JDK-8364611 (Bug - P4)

Reviewers

• Albert Mingkun Yang (@albertnetymk - Reviewer)
• Matthias Baesken (@MBaesken - Reviewer)

Reviewing

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[bridgekeeper]

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[openjdk]

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

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

8365296: Build failure with Clang due to -Wformat warning after JDK-8364611

Reviewed-by: ayang, mbaesken

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

At the time when this comment was updated there had been 16 new commits pushed to the master branch:

• 5856dc3: 8365199: Use a set instead of a list as the intermediary Klass* storage to reduce typeset processing
• fa2eb61: 8365491: VSCode IDE: add basic configuration for the Oracle Java extension
• e3aeebe: 8365468: EagerJVMCI should only apply to the CompilerBroker JVMCI runtime
• ... and 13 more: https://git.openjdk.org/jdk/compare/e320162815d529bc65cd058b34ec39d60d032ce7...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.

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➡️ 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).

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[mlbridge]

Webrevs

• 03: Full - Incremental (30961273)
• 02: Full - Incremental (6077719c)
• 01: Full - Incremental (207cc292)
• 00: Full (b6f672b5)

[MBaesken]

Seems there is also coding in os_posix.cpp ( describe_signal_set_short ) to print signal information , maybe 'borrow' from there?

[hgqxjj]

Hi @MBaesken
Thanks for the suggestion! I’ve updated the code as you requested. Please take a look when you have time.

[albertnetymk]

The fix looks reasonable. However, the discrepancy btw and AIX and others seems unnecessary complexity. I'd prefer having ifdef removed also.

Looking at how these prints are used/tested, I believe sa_mask is not really needed and it doesn't seem very useful also. Therefore, I'd suggest removing it, just like what's done for AIX. My 2c.

[hgqxjj]

hi @albertnetymk , thanks for the feedback! I agree that removing it would be the simplest solution.
Let’s get @MBaesken input as well, and if we reach an agreement, I’m happy to proceed with the simplest approach.

[shqking]

nit: XX, YY, means that this file was created in XX year and the latest update is done in YY year. If XX == YY, then use XX,.

Suggested change

	* Copyright (c) 2025, Oracle and/or its affiliates. All rights reserved.
	* Copyright (c) 2021, 2025, Oracle and/or its affiliates. All rights reserved.

[hgqxjj]

Hi @shqking , thanks for the suggestion! I checked the file history, and it was actually created in 2025. Therefore, I updated the copyright to Copyright (c) 2025 to reflect the correct creation year. If the file gets updated in the future, we can follow the “XX, YY” format.

[MBaesken]

The fix looks reasonable. However, the discrepancy btw and AIX and others seems unnecessary complexity. I'd prefer having ifdef removed also.

Looking at how these prints are used/tested, I believe sa_mask is not really needed and it doesn't seem very useful also. Therefore, I'd suggest removing it, just like what's done for AIX. My 2c.

That's fine .

[hgqxjj]

@MBaesken @albertnetymk
Thanks for the feedback. I’ve removed the sa_mask printing as suggested. Please take another look when you have time.

[hgqxjj]

/integrate

[openjdk]

@hgqxjj
Your change (at version 3096127) is now ready to be sponsored by a Committer.

[hgqxjj]

Many thanks to both of you @MBaesken @albertnetymk for your review and approval. I’ve integrated the changes.
Please sponsor it — appreciate it!

[MBaesken]

/sponsor

[openjdk]

Going to push as commit b6d5f49.
Since your change was applied there have been 16 commits pushed to the master branch:

• 5856dc3: 8365199: Use a set instead of a list as the intermediary Klass* storage to reduce typeset processing
• fa2eb61: 8365491: VSCode IDE: add basic configuration for the Oracle Java extension
• e3aeebe: 8365468: EagerJVMCI should only apply to the CompilerBroker JVMCI runtime
• ... and 13 more: https://git.openjdk.org/jdk/compare/e320162815d529bc65cd058b34ec39d60d032ce7...master

Your commit was automatically rebased without conflicts.

[openjdk]

@MBaesken @hgqxjj Pushed as commit b6d5f49.

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