8342206: Convenience method to check if a ClassEntry matches a ClassDesc

[liach]

Currently, to efficiently check if a ClassEntry, such as one from an InvokeInstruction, is of a particular class, we use such a pattern (as seen in JEP 486 Appendix):

inst.owner().name().equalsString("java/lang/System")

This pattern has a few issues:

1. This is not straightforward. Users may be tempted to write

inst.owner().asSymbol().equals(CD_System)

unaware of the degraded performance from extra conversions.

2. We aim to reduce the use of "internal names" with encapsulation. Direct use of "java/lang/System" goes against this, and we have no constants offered to reduce such error-prone use of internal name.

Thus, I propose a new API in ClassEntry:

boolean equalsSymbol(ClassDesc)

that can be used conveniently to check the identity of a class entry with a clean syntax and better performance.

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Progress

• [ ] Change must be properly reviewed (1 review required, with at least 1 Reviewer)
• [x] Change must not contain extraneous whitespace
• [x] Commit message must refer to an issue
• [ ] Change requires CSR request JDK-8342210 to be approved

Issues

• JDK-8342206: Convenience method to check if a ClassEntry matches a ClassDesc (Enhancement - P4)
• JDK-8342210: Convenience method to check if a ClassEntry matches a ClassDesc (CSR)

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[ExE-Boss]

I think it might be a good idea to also have equalsSymbol(…) methods for the other pool entries.

[liach]

I think it might be a good idea to also have equalsSymbol(…) methods for the other pool entries.

Indeed, this can avoid promotion to String state for all applicable symbols. I decide to start with the ClassEntry as this is the most error-prone and worth optimization. (Feel free to submit a ticket through bugs.java.com)

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