8361730: The CodeBuilder.trying(BlockCodeBuilder,CatchBuilder) method generates corrupted bytecode in certain cases

[liach]

Explicitly document that BlockCodeBuilder expects control flow to continue after it merges back to the parent block, so failure to do that by the users can lead to malformed code. This is better than introducing complex and costly analysis.

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Progress

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• Commit message must refer to an issue
• Change requires CSR request JDK-8364553 to be approved

Issues

• JDK-8361730: The CodeBuilder.trying(BlockCodeBuilder,CatchBuilder) method generates corrupted bytecode in certain cases (Bug - P3)
• JDK-8364553: BlockCodeBuilder may generate corrupted bytecode if its break has no subsequent code (CSR)

Reviewers

• Adam Sotona (@asotona - Reviewer)

Reviewing

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[bridgekeeper]

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[openjdk]

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

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8361730: The CodeBuilder.trying(BlockCodeBuilder,CatchBuilder) method generates corrupted bytecode in certain cases

Reviewed-by: asotona

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At the time when this comment was updated there had been 127 new commits pushed to the master branch:

• 9c266ae: 8365229: ARM32: c2i_no_clinit_check_entry assert failed after JDK-8364269
• 9660320: 8364781: Re-examine DigitList digits resizing during parsing
• 4680dc9: 8365264: Rename ResourceHashtable to HashTable
• ... and 124 more: https://git.openjdk.org/jdk/compare/ee3665bca026fe53409df8391d49477c64ae23a2...master

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[mlbridge]

Webrevs

• 00: Full (9cb3bc95)

[ExE-Boss]

I think that the trying builder could be improved to only insert the goto branchLabel when the last instruction or pseudo‑instruction isn’t a ReturnInstruction, a ThrowInstruction, or a BranchInstruction.

[liach]

I don't think your suggestion work when one block code builder ends immediately with another block code builder. The enclosing one may require the goto if the nested one breaks to its break label.

[asotona]

Looks good to me, thanks.

[liach]

Thanks for the reviews!

/integrate

[openjdk]

Going to push as commit c5cbcac.
Since your change was applied there have been 140 commits pushed to the master branch:

• dccca0f: 8365572: Shenandoah: Remove unused thread local _paced_time field
• ba23105: 8365048: idea.sh script does not correctly detect/handle git worktrees
• 26ccb3c: 8362530: VM crash with -XX:+PrintTieredEvents when collecting AOT profiling
• ... and 137 more: https://git.openjdk.org/jdk/compare/ee3665bca026fe53409df8391d49477c64ae23a2...master

Your commit was automatically rebased without conflicts.

[openjdk]

@liach Pushed as commit c5cbcac.

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