8272776: NullPointerException not reported

[lahodaj]

Code like:

public void foo(Object o) {
        switch (o) {
          default: break;
          case String s :System.out.println(s); break;
        } 
}
public static void main(String[] args) {
        (new X()).foo(null); // NPE expected, but prints null
}

Should lead to a NPE when executed, because default does not cover null and there is no total pattern in the switch, but the NPE is not thrown. The reason is that when generating the code, a hasTotalPattern flag is used, which means "has a total pattern or default". The code needs to check whether there is a real total pattern (which covers null) or not. That is done by looking for the default case label, but the code only checks the last case for default. It needs to check all cases to differentiate between a switch with a real total pattern and a switch with a default.

---

Progress

• Change must not contain extraneous whitespace
• Commit message must refer to an issue
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Issue

• JDK-8272776: NullPointerException not reported

Reviewers

• Vicente Romero (@vicente-romero-oracle - Reviewer)

Reviewing

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[openjdk]

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[mlbridge]

Webrevs

• 00: Full (6d67de8b)

[vicente-romero-oracle]

looks sensible

[openjdk]

@lahodaj 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:

8272776: NullPointerException not reported

Reviewed-by: vromero

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 237 new commits pushed to the master branch:

• 5245c1c: 8273147: Update and restructure TestGCLogMessages log message list
• 632a7e0: 8273165: GraphKit::combine_exception_states fails with "matching stack sizes" assert
• c2e015c: 8273229: Update OS detection code to recognize Windows Server 2022
• 0c1b16b: 8273243: Fix indentations in java.net.InetAddress methods
• 152e669: 8273140: Replace usages of Enum.class.getEnumConstants() with Enum.values() where possible
• 857a930: 8263375: Support stack watermarks in Zero VM
• 6cfe314: 8272970: Parallelize runtime/InvocationTests/
• a9a83b2: 8273256: runtime/cds/appcds/TestEpsilonGCWithCDS.java fails due to Unrecognized VM option 'ObjectAlignmentInBytes=64' on x86_32
• 1a5a2b6: 8271745: Correct block size for KW,KWP mode and use fixed IV for KWP mode for SunJCE
• 2f01a6f: 8273157: Add convenience methods to Messager
• ... and 227 more: https://git.openjdk.java.net/jdk/compare/a86ac0d1e3a6f02e587362c767abdf62b308d321...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.

[lahodaj]

/integrate

[openjdk]

Going to push as commit 93eec9a.
Since your change was applied there have been 246 commits pushed to the master branch:

• 7b023a3: 8273257: jshell doesn't compile a sealed hierarchy with a sealed interface and a non-sealed leaf
• f17ee0c: 8273263: Incorrect recovery attribution of record component type when j.l.Record is unavailable
• fa9c865: 8273112: -Xloggc: should override -verbose:gc
• dd87181: 8214761: Bug in parallel Kahan summation implementation
• 7fff22a: 8272805: Avoid looking up standard charsets
• 92b05fe: 8273251: Call check_possible_safepoint() from SafepointMechanism::process_if_requested()
• 29e0f13: 8272385: Enforce ECPrivateKey d value to be in the range [1, n-1] for SunEC provider
• aaa6f69: 8273250: Address javadoc issues in Deflater::setDictionationary
• 5ee5dd9: 8272914: Create hotspot:tier2 and hotspot:tier3 test groups
• 5245c1c: 8273147: Update and restructure TestGCLogMessages log message list
• ... and 236 more: https://git.openjdk.java.net/jdk/compare/a86ac0d1e3a6f02e587362c767abdf62b308d321...master

Your commit was automatically rebased without conflicts.

[openjdk]

@lahodaj Pushed as commit 93eec9a.

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