8282194: C1: Missing side effects of dynamic constant linkage

[iwanowww]

After JDK-8280473, C1 handles unresolved dynamic constants by performing
constant resolution at runtime and then putting the constant value into the
generated code by patching it. But it treats the not-yet-resolved constant as a
pure value, dynamic constants are produced by user-defined bootstrap methods
and there are no guarantees that they don't have any side effects.

Proposed fix conservatively kills the whole memory state after any unresolved
dynamic constant.

Testing:

• jck:vm/constantpool/resolveDynamicConstant w/ -Xcomp
• hs-tier1 - hs-tier4

---

Progress

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Issue

• JDK-8282194: C1: Missing side effects of dynamic constant linkage

Reviewers

• Vladimir Kozlov (@vnkozlov - Reviewer)
• Tobias Hartmann (@TobiHartmann - Reviewer)

Reviewing

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[mlbridge]

Webrevs

• 00: Full (116518b9)

[iwanowww]

Forgot to mention that the problem is not specific to dynamic constants. It turns out all non-String constants are affected, because their linkage involves class loading. Custom class loaders may produce (provide no guarantees) side effects which are noticeable by an application, but not necessarily preserved across a patched constant in C1-generated code. Filed JDK-8282218 to cover such cases.

[vnkozlov]

Good.

[openjdk]

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

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

8282194: C1: Missing side effects of dynamic constant linkage

Reviewed-by: kvn, thartmann

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At the time when this comment was updated there had been 29 new commits pushed to the master branch:

• e1060be: 8281615: Deadlock caused by jdwp agent
• 6f882de: 8280964: [Linux aarch64] : drawImage dithers TYPE_BYTE_INDEXED images incorrectly
• 2557ef8: 8282276: Problem list failing two Robot Screen Capture tests
• 6445ee4: 5041655: (ch) FileLock: negative param and overflow issues
• 7feabee: 8261407: ReflectionFactory.checkInitted() is not thread-safe
• 58e1882: 8282042: [testbug] FileEncodingTest.java depends on default encoding
• 3cb3867: 8281315: Unicode, (?i) flag and backreference throwing IndexOutOfBounds Exception
• 957dae0: 8280958: G1/Parallel: Unify marking code structure
• e44d067: 8244593: Clean up GNM/NM after JEP 381
• 41355e2: 8276686: Malformed Javadoc inline tags in JDK source in /java/util/regex/Pattern.java
• ... and 19 more: https://git.openjdk.java.net/jdk/compare/3943c89b9b71d8c1fda3ba88fd833f08723202f0...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.

[TobiHartmann]

Looks good. Is it worth adding a regression test?

[iwanowww]

Thanks for the reviews, Vladimir and Tobias.

Is it worth adding a regression test?

Strictly speaking, jck:vm/constantpool/resolveDynamicConstant tests catch the problem.
But I plan to add new test as part of JDK-8282218. Will consider adding a case for dynamic constants there.

/integrate

[openjdk]

Going to push as commit 9332071.
Since your change was applied there have been 31 commits pushed to the master branch:

• ecd85e6: 8282231: x86-32: runtime call to SharedRuntime::ldiv corrupts registers
• 378fa50: 8281962: Avoid unnecessary native calls in InflaterInputStream
• e1060be: 8281615: Deadlock caused by jdwp agent
• 6f882de: 8280964: [Linux aarch64] : drawImage dithers TYPE_BYTE_INDEXED images incorrectly
• 2557ef8: 8282276: Problem list failing two Robot Screen Capture tests
• 6445ee4: 5041655: (ch) FileLock: negative param and overflow issues
• 7feabee: 8261407: ReflectionFactory.checkInitted() is not thread-safe
• 58e1882: 8282042: [testbug] FileEncodingTest.java depends on default encoding
• 3cb3867: 8281315: Unicode, (?i) flag and backreference throwing IndexOutOfBounds Exception
• 957dae0: 8280958: G1/Parallel: Unify marking code structure
• ... and 21 more: https://git.openjdk.java.net/jdk/compare/3943c89b9b71d8c1fda3ba88fd833f08723202f0...master

Your commit was automatically rebased without conflicts.

[openjdk]

@iwanowww Pushed as commit 9332071.

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