8271254: javac generates unreachable code when using empty semicolon statement

[lgxbslgx]

Hi all,

The method Gen#genTry is used by visitTry and visitSynchronized, but genTry can't identify who is invoking it so that it can't solve the concrete issues about try statement or synchronized statement separately. This patch adds a new parameter actualTry to identify the concrete situation( try or synchronized) and fixes this issue about using empty skip statement in the try statement body. And some related test cases are added.

Thanks for taking the time to review.

Best Regards,
-- Guoxiong

---

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Issue

• JDK-8271254: javac generates unreachable code when using empty semicolon statement

Reviewers

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

Reviewing

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[bridgekeeper]

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[mlbridge]

Webrevs

• 01: Full - Incremental (f9c870c8)
• 00: Full (0f6f3cdd)

[vicente-romero-oracle]

I don't think you really need an additional argument, I think that you can check for the tree at the env argument and you should be able to find out if this method is being invoked from a try or not. Kind of:

boolean actualTry = env.tree.hasTag(TRY);

[lgxbslgx]

@vicente-romero-oracle you are right. I updated the code just now by using the env instead of the new parameter.

[vicente-romero-oracle]

looks good

[openjdk]

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

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

8271254: javac generates unreachable code when using empty semicolon statement

Reviewed-by: vromero

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At the time when this comment was updated there had been 26 new commits pushed to the master branch:

• 8974b95: 8273730: WorkGangBarrierSync constructor unused
• 1d3eb14: 8273635: Attempting to acquire lock StackWatermark_lock/9 out of order with lock tty_lock/3
• 31667da: 8273491: java.util.spi.LocaleServiceProvider spec contains statement that is too strict
• ed7789d: 8256977: Bump minimum GCC from 5.x to 6 for JDK
• 5bfd043: 8273497: building.md should link to both md and html
• 3884580: 8273597: Rectify Thread::is_ConcurrentGC_thread()
• f527289: 8273639: tests fail with "assert(_handle_mark_nesting > 1) failed: memory leak: allocating handle outside HandleMark"
• 1d2458d: 8266550: C2: mirror TypeOopPtr/TypeInstPtr/TypeAryPtr with TypeKlassPtr/TypeInstKlassPtr/TypeAryKlassPtr
• a143372: 8273438: Enable parallelism in vmTestbase/metaspace/stressHierarchy tests
• 86a8e55: 8273486: Zero: Handle DiagnoseSyncOnValueBasedClasses VM option
• ... and 16 more: https://git.openjdk.java.net/jdk/compare/f189dff5cbd4d47e1b2f3c0e5f2c866a7effccdf...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.

[lgxbslgx]

@vicente-romero-oracle Thanks for your review.

/integrate

[openjdk]

Going to push as commit fe89dd3.
Since your change was applied there have been 26 commits pushed to the master branch:

• 8974b95: 8273730: WorkGangBarrierSync constructor unused
• 1d3eb14: 8273635: Attempting to acquire lock StackWatermark_lock/9 out of order with lock tty_lock/3
• 31667da: 8273491: java.util.spi.LocaleServiceProvider spec contains statement that is too strict
• ed7789d: 8256977: Bump minimum GCC from 5.x to 6 for JDK
• 5bfd043: 8273497: building.md should link to both md and html
• 3884580: 8273597: Rectify Thread::is_ConcurrentGC_thread()
• f527289: 8273639: tests fail with "assert(_handle_mark_nesting > 1) failed: memory leak: allocating handle outside HandleMark"
• 1d2458d: 8266550: C2: mirror TypeOopPtr/TypeInstPtr/TypeAryPtr with TypeKlassPtr/TypeInstKlassPtr/TypeAryKlassPtr
• a143372: 8273438: Enable parallelism in vmTestbase/metaspace/stressHierarchy tests
• 86a8e55: 8273486: Zero: Handle DiagnoseSyncOnValueBasedClasses VM option
• ... and 16 more: https://git.openjdk.java.net/jdk/compare/f189dff5cbd4d47e1b2f3c0e5f2c866a7effccdf...master

Your commit was automatically rebased without conflicts.

[openjdk]

@lgxbslgx Pushed as commit fe89dd3.

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