8316907: Fix nonnull-compare warnings

[djelinski]

Please review this patch that fixes nonnull-compare warnings emitted by GCC after removing -fno-delete-null-pointer-checks.

The changes are pretty straightforward:

• removal of assert(this) only changes the behavior of debug code; assertion failure in that place would result in a crash later on,
• the check in CodeBuffer::print is a bit more complex to review; fortunately all uses except print_buf_locs are in CodeBuffer, and print_buf_locs is only used by developers from debugger.

I verified tier1-5 tests, just in case. No new failures.

---

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-8316907: Fix nonnull-compare warnings (Sub-task - P4)

Reviewers

• Kim Barrett (@kimbarrett - Reviewer)
• Johan Sjölen (@jdksjolen - Reviewer)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk.git pull/15927/head:pull/15927
$ git checkout pull/15927

Update a local copy of the PR:
$ git checkout pull/15927
$ git pull https://git.openjdk.org/jdk.git pull/15927/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 15927

View PR using the GUI difftool:
$ git pr show -t 15927

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk/pull/15927.diff

Webrev

Link to Webrev Comment

[bridgekeeper]

👋 Welcome back djelinski! 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]

@djelinski The following label will be automatically applied to this pull request:

• hotspot-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

• 00: Full (601f6f5a)

[kimbarrett]

Looks good.

[openjdk]

@djelinski 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:

8316907: Fix nonnull-compare warnings

Reviewed-by: kbarrett, jsjolen

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 69 new commits pushed to the master branch:

• eeb63cd: 8316361: C2: assert(!failure) failed: Missed optimization opportunity in PhaseIterGVN with -XX:VerifyIterativeGVN=10
• 6948942: 8317327: Remove JT_JAVA dead code in jib-profiles.js
• 795e5dc: 8315503: G1: Code root scan causes long GC pauses due to imbalanced iteration
• 207819a: 8315604: IGV: dump and visualize node bottom and phase types
• 8fcf70e: 5066247: Refine the spec of equals() and hashCode() for j.text.Format classes
• 93f662f: 8317335: Build on windows fails after 8316645
• b8fa6c2: 8316186: RISC-V: Remove PlatformCmpxchg<4>
• fb055e7: 8316645: RISC-V: Remove dependency on libatomic by adding cmpxchg 1b
• 009f5e1: 8317141: Remove unused validIndex method from URLClassPath$JarLoader
• 47569a2: 8295919: java.security.MessageDigest.isEqual does not adhere to @implNote
• ... and 59 more: https://git.openjdk.org/jdk/compare/1f7dfda7059f9dc14bff61b3c77d769ade85557d...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.

➡️ To integrate this PR with the above commit message to the master branch, type /integrate in a new comment.

[jdksjolen]

Thank you, this looks good to me.

[djelinski]

Thanks for the reviews!

/integrate

[openjdk]

Going to push as commit 516cfb1.
Since your change was applied there have been 70 commits pushed to the master branch:

• 5984792: 8316415: Parallelize sun/security/rsa/SignedObjectChain.java subtests
• eeb63cd: 8316361: C2: assert(!failure) failed: Missed optimization opportunity in PhaseIterGVN with -XX:VerifyIterativeGVN=10
• 6948942: 8317327: Remove JT_JAVA dead code in jib-profiles.js
• 795e5dc: 8315503: G1: Code root scan causes long GC pauses due to imbalanced iteration
• 207819a: 8315604: IGV: dump and visualize node bottom and phase types
• 8fcf70e: 5066247: Refine the spec of equals() and hashCode() for j.text.Format classes
• 93f662f: 8317335: Build on windows fails after 8316645
• b8fa6c2: 8316186: RISC-V: Remove PlatformCmpxchg<4>
• fb055e7: 8316645: RISC-V: Remove dependency on libatomic by adding cmpxchg 1b
• 009f5e1: 8317141: Remove unused validIndex method from URLClassPath$JarLoader
• ... and 60 more: https://git.openjdk.org/jdk/compare/1f7dfda7059f9dc14bff61b3c77d769ade85557d...master

Your commit was automatically rebased without conflicts.

[openjdk]

@djelinski Pushed as commit 516cfb1.

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